diff --git a/.changeset/tiny-panthers-jump.md b/.changeset/tiny-panthers-jump.md
new file mode 100644
index 0000000000..d059b826da
--- /dev/null
+++ b/.changeset/tiny-panthers-jump.md
@@ -0,0 +1,22 @@
+---
+'@backstage/backend-common': patch
+'@backstage/cli': patch
+'@backstage/config-loader': patch
+'@backstage/core-app-api': patch
+'@backstage/core-components': patch
+'@backstage/core-plugin-api': patch
+'@backstage/create-app': patch
+'@backstage/techdocs-common': patch
+'@backstage/plugin-auth-backend': patch
+'@backstage/plugin-catalog': patch
+'@backstage/plugin-catalog-backend': patch
+'@backstage/plugin-catalog-backend-module-ldap': patch
+'@backstage/plugin-catalog-import': patch
+'@backstage/plugin-catalog-react': patch
+'@backstage/plugin-code-coverage-backend': patch
+'@backstage/plugin-kubernetes-backend': patch
+'@backstage/plugin-scaffolder-backend': patch
+'@backstage/plugin-techdocs-backend': patch
+---
+
+Internal updates to apply more strict checks to throw errors.
diff --git a/packages/backend-common/src/database/connectors/postgres.ts b/packages/backend-common/src/database/connectors/postgres.ts
index f6e42d1945..62de2e001e 100644
--- a/packages/backend-common/src/database/connectors/postgres.ts
+++ b/packages/backend-common/src/database/connectors/postgres.ts
@@ -17,6 +17,7 @@
 import knexFactory, { Knex } from 'knex';
 
 import { Config } from '@backstage/config';
+import { ForwardedError } from '@backstage/errors';
 import { mergeDatabaseConfig } from '../config';
 import { DatabaseConnector } from '../types';
 import defaultNameOverride from './defaultNameOverride';
@@ -94,8 +95,7 @@ function requirePgConnectionString() {
   try {
     return require('pg-connection-string').parse;
   } catch (e) {
-    const message = `Postgres: Install 'pg-connection-string'`;
-    throw new Error(`${message}\n${e.message}`);
+    throw new ForwardedError("Postgres: Install 'pg-connection-string'", e);
   }
 }
 
diff --git a/packages/backend-common/src/reading/AwsS3UrlReader.test.ts b/packages/backend-common/src/reading/AwsS3UrlReader.test.ts
index 0bc0e4f97f..6959edcc8b 100644
--- a/packages/backend-common/src/reading/AwsS3UrlReader.test.ts
+++ b/packages/backend-common/src/reading/AwsS3UrlReader.test.ts
@@ -167,7 +167,7 @@ describe('AwsS3UrlReader', () => {
         ),
       ).rejects.toThrow(
         Error(
-          `Could not retrieve file from S3: not a valid AWS S3 URL: https://test-bucket.s3.us-east-2.NOTamazonaws.com/file.yaml`,
+          `Could not retrieve file from S3; caused by Error: not a valid AWS S3 URL: https://test-bucket.s3.us-east-2.NOTamazonaws.com/file.yaml`,
         ),
       );
     });
@@ -216,7 +216,7 @@ describe('AwsS3UrlReader', () => {
         ),
       ).rejects.toThrow(
         Error(
-          `Could not retrieve file from S3: not a valid AWS S3 URL: https://test-bucket.s3.us-east-2.NOTamazonaws.com/file.yaml`,
+          `Could not retrieve file from S3; caused by Error: not a valid AWS S3 URL: https://test-bucket.s3.us-east-2.NOTamazonaws.com/file.yaml`,
         ),
       );
     });
diff --git a/packages/backend-common/src/reading/AwsS3UrlReader.ts b/packages/backend-common/src/reading/AwsS3UrlReader.ts
index cb03ec4f71..7fd0f6ba19 100644
--- a/packages/backend-common/src/reading/AwsS3UrlReader.ts
+++ b/packages/backend-common/src/reading/AwsS3UrlReader.ts
@@ -27,6 +27,7 @@ import {
 } from './types';
 import getRawBody from 'raw-body';
 import { AwsS3Integration, ScmIntegrations } from '@backstage/integration';
+import { ForwardedError } from '@backstage/errors';
 import { ListObjectsV2Output, ObjectList } from 'aws-sdk/clients/s3';
 
 const parseURL = (
@@ -162,7 +163,7 @@ export class AwsS3UrlReader implements UrlReader {
         etag: etag,
       };
     } catch (e) {
-      throw new Error(`Could not retrieve file from S3: ${e.message}`);
+      throw new ForwardedError('Could not retrieve file from S3', e);
     }
   }
 
@@ -203,7 +204,7 @@ export class AwsS3UrlReader implements UrlReader {
 
       return await this.deps.treeResponseFactory.fromReadableArray(responses);
     } catch (e) {
-      throw new Error(`Could not retrieve file tree from S3: ${e.message}`);
+      throw new ForwardedError('Could not retrieve file tree from S3', e);
     }
   }
 
diff --git a/packages/backend-common/src/reading/integration.test.ts b/packages/backend-common/src/reading/integration.test.ts
index ae557be583..951df29605 100644
--- a/packages/backend-common/src/reading/integration.test.ts
+++ b/packages/backend-common/src/reading/integration.test.ts
@@ -15,6 +15,7 @@
  */
 
 import { ConfigReader } from '@backstage/config';
+import { isError } from '@backstage/errors';
 import { getVoidLogger } from '../logging';
 import { UrlReaders } from './UrlReaders';
 
@@ -71,7 +72,10 @@ function withRetries(count: number, fn: () => Promise<void>) {
         error = err;
       }
     }
-    if (!error.message.match(/rate limit|Too Many Requests/)) {
+    if (
+      isError(error) &&
+      !error.message.match(/rate limit|Too Many Requests/)
+    ) {
       throw error;
     } else {
       console.warn('Request was rate limited', error);
diff --git a/packages/backend-common/src/util/DockerContainerRunner.ts b/packages/backend-common/src/util/DockerContainerRunner.ts
index da3ce66ec2..b81bd995ca 100644
--- a/packages/backend-common/src/util/DockerContainerRunner.ts
+++ b/packages/backend-common/src/util/DockerContainerRunner.ts
@@ -16,6 +16,7 @@
 
 import Docker from 'dockerode';
 import fs from 'fs-extra';
+import { ForwardedError } from '@backstage/errors';
 import { PassThrough } from 'stream';
 import { ContainerRunner, RunContainerOptions } from './ContainerRunner';
 
@@ -45,8 +46,9 @@ export class DockerContainerRunner implements ContainerRunner {
     try {
       await this.dockerClient.ping();
     } catch (e) {
-      throw new Error(
-        `This operation requires Docker. Docker does not appear to be available. Docker.ping() failed with: ${e.message}`,
+      throw new ForwardedError(
+        'This operation requires Docker. Docker does not appear to be available. Docker.ping() failed with',
+        e,
       );
     }
 
diff --git a/packages/cli/package.json b/packages/cli/package.json
index ecc3d3b4e1..ebd8f0169c 100644
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -31,6 +31,7 @@
     "@backstage/cli-common": "^0.1.4",
     "@backstage/config": "^0.1.10",
     "@backstage/config-loader": "^0.6.10",
+    "@backstage/errors": "^0.1.2",
     "@hot-loader/react-dom": "^16.13.0",
     "@lerna/package-graph": "^4.0.0",
     "@lerna/project": "^4.0.0",
diff --git a/packages/cli/src/commands/create-plugin/createPlugin.ts b/packages/cli/src/commands/create-plugin/createPlugin.ts
index 6ddd1f7160..a5ea565cae 100644
--- a/packages/cli/src/commands/create-plugin/createPlugin.ts
+++ b/packages/cli/src/commands/create-plugin/createPlugin.ts
@@ -24,6 +24,7 @@ import camelCase from 'lodash/camelCase';
 import upperFirst from 'lodash/upperFirst';
 import os from 'os';
 import { Command } from 'commander';
+import { assertError } from '@backstage/errors';
 import {
   parseOwnerIds,
   addCodeownersEntry,
@@ -173,6 +174,7 @@ async function buildPlugin(pluginFolder: string) {
         );
       });
     } catch (error) {
+      assertError(error);
       Task.error(error.message);
       break;
     }
@@ -329,6 +331,7 @@ export default async (cmd: Command) => {
     Task.log();
     Task.exit();
   } catch (error) {
+    assertError(error);
     Task.error(error.message);
 
     Task.log('It seems that something went wrong when creating the plugin 🤔');
diff --git a/packages/cli/src/commands/index.ts b/packages/cli/src/commands/index.ts
index d6686f2655..302f76cc5d 100644
--- a/packages/cli/src/commands/index.ts
+++ b/packages/cli/src/commands/index.ts
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+import { assertError } from '@backstage/errors';
 import { CommanderStatic } from 'commander';
 import { exitWithError } from '../lib/errors';
 
@@ -252,6 +253,7 @@ function lazy(
 
       process.exit(0);
     } catch (error) {
+      assertError(error);
       exitWithError(error);
     }
   };
diff --git a/packages/cli/src/commands/remove-plugin/removePlugin.ts b/packages/cli/src/commands/remove-plugin/removePlugin.ts
index 9e1e18bb7b..11fdc8bb11 100644
--- a/packages/cli/src/commands/remove-plugin/removePlugin.ts
+++ b/packages/cli/src/commands/remove-plugin/removePlugin.ts
@@ -20,6 +20,7 @@ import inquirer, { Answers, Question } from 'inquirer';
 import { getCodeownersFilePath } from '../../lib/codeowners';
 import { paths } from '../../lib/paths';
 import { Task } from '../../lib/tasks';
+import { assertError } from '@backstage/errors';
 
 const BACKSTAGE = '@backstage';
 
@@ -35,6 +36,7 @@ export const checkExists = async (rootDir: string, pluginName: string) => {
         );
       }
     } catch (e) {
+      assertError(e);
       throw new Error(
         chalk.red(
           `   There was an error removing plugin ${chalk.cyan(pluginName)}: ${
@@ -51,6 +53,7 @@ export const removePluginDirectory = async (destination: string) => {
     try {
       await fse.remove(destination);
     } catch (e) {
+      assertError(e);
       throw Error(
         chalk.red(
           `   There was a problem removing the plugin directory: ${e.message}`,
@@ -67,6 +70,7 @@ export const removeSymLink = async (destination: string) => {
       try {
         await fse.remove(destination);
       } catch (e) {
+        assertError(e);
         throw Error(
           chalk.red(
             `   Could not remove symbolic link\t${chalk.cyan(destination)}: ${
@@ -106,6 +110,7 @@ export const removeReferencesFromPluginsFile = async (
     try {
       await removeAllStatementsContainingID(pluginsFile, pluginNameCapitalized);
     } catch (e) {
+      assertError(e);
       throw new Error(
         chalk.red(
           `   There was an error removing export statement for plugin ${chalk.cyan(
@@ -125,6 +130,7 @@ export const removePluginFromCodeOwners = async (
     try {
       await removeAllStatementsContainingID(codeOwnersFile, pluginName);
     } catch (e) {
+      assertError(e);
       throw new Error(
         chalk.red(
           `   There was an error removing code owners statement for plugin ${chalk.cyan(
@@ -165,6 +171,7 @@ export const removeReferencesFromAppPackage = async (
         'utf-8',
       );
     } catch (e) {
+      assertError(e);
       throw new Error(
         chalk.red(
           `  Failed to remove plugin as dependency in app: ${chalk.cyan(
@@ -245,6 +252,7 @@ export default async () => {
     );
     Task.log();
   } catch (error) {
+    assertError(error);
     Task.error(error.message);
     Task.log('It seems that something went wrong when removing the plugin 🤔');
   }
diff --git a/packages/cli/src/commands/versions/bump.ts b/packages/cli/src/commands/versions/bump.ts
index 257a83e2be..7b967839b2 100644
--- a/packages/cli/src/commands/versions/bump.ts
+++ b/packages/cli/src/commands/versions/bump.ts
@@ -17,6 +17,7 @@
 import fs from 'fs-extra';
 import chalk from 'chalk';
 import semver from 'semver';
+import { isError } from '@backstage/errors';
 import { resolve as resolvePath } from 'path';
 import { run } from '../../lib/run';
 import { paths } from '../../lib/paths';
@@ -59,7 +60,7 @@ export default async () => {
     try {
       target = await findTargetVersion(name);
     } catch (error) {
-      if (error.name === 'NotFoundError') {
+      if (isError(error) && error.name === 'NotFoundError') {
         console.log(`Package info not found, ignoring package ${name}`);
         return;
       }
@@ -97,7 +98,7 @@ export default async () => {
     try {
       target = await findTargetVersion(name);
     } catch (error) {
-      if (error.name === 'NotFoundError') {
+      if (isError(error) && error.name === 'NotFoundError') {
         console.log(`Package info not found, ignoring package ${name}`);
         return;
       }
diff --git a/packages/cli/src/lib/run.ts b/packages/cli/src/lib/run.ts
index 7cf22a6df9..4efb791c30 100644
--- a/packages/cli/src/lib/run.ts
+++ b/packages/cli/src/lib/run.ts
@@ -23,6 +23,7 @@ import {
 import { ExitCodeError } from './errors';
 import { promisify } from 'util';
 import { LogFunc } from './logging';
+import { assertError, ForwardedError } from '@backstage/errors';
 
 const execFile = promisify(execFileCb);
 
@@ -75,10 +76,14 @@ export async function runPlain(cmd: string, ...args: string[]) {
     const { stdout } = await execFile(cmd, args, { shell: true });
     return stdout.trim();
   } catch (error) {
-    if (error.stderr) {
-      process.stderr.write(error.stderr);
+    assertError(error);
+    if ('stderr' in error) {
+      process.stderr.write(error.stderr as Buffer);
     }
-    throw new ExitCodeError(error.code, [cmd, ...args].join(' '));
+    if (typeof error.code === 'number') {
+      throw new ExitCodeError(error.code, [cmd, ...args].join(' '));
+    }
+    throw new ForwardedError('Unknown execution error', error);
   }
 }
 
diff --git a/packages/config-loader/package.json b/packages/config-loader/package.json
index a719c6389b..ebca3ffdf3 100644
--- a/packages/config-loader/package.json
+++ b/packages/config-loader/package.json
@@ -32,6 +32,7 @@
   "dependencies": {
     "@backstage/cli-common": "^0.1.4",
     "@backstage/config": "^0.1.9",
+    "@backstage/errors": "^0.1.2",
     "@types/json-schema": "^7.0.6",
     "ajv": "^7.0.3",
     "chokidar": "^3.5.2",
diff --git a/packages/config-loader/src/lib/env.ts b/packages/config-loader/src/lib/env.ts
index b244c06c64..57cfc077a7 100644
--- a/packages/config-loader/src/lib/env.ts
+++ b/packages/config-loader/src/lib/env.ts
@@ -15,6 +15,7 @@
  */
 
 import { AppConfig, JsonObject } from '@backstage/config';
+import { assertError } from '@backstage/errors';
 
 const ENV_PREFIX = 'APP_CONFIG_';
 
@@ -96,6 +97,7 @@ function safeJsonParse(str: string): [Error | null, any] {
   try {
     return [null, JSON.parse(str)];
   } catch (err) {
+    assertError(err);
     return [err, str];
   }
 }
diff --git a/packages/config-loader/src/lib/schema/collect.ts b/packages/config-loader/src/lib/schema/collect.ts
index f8b134119b..de6aff376f 100644
--- a/packages/config-loader/src/lib/schema/collect.ts
+++ b/packages/config-loader/src/lib/schema/collect.ts
@@ -24,6 +24,7 @@ import {
 import { ConfigSchemaPackageEntry } from './types';
 import { getProgramFromFiles, generateSchema } from 'typescript-json-schema';
 import { JsonObject } from '@backstage/config';
+import { assertError } from '@backstage/errors';
 
 type Item = {
   name?: string;
@@ -189,6 +190,7 @@ function compileTsSchemas(paths: string[]) {
         [path.split(sep).join('/')], // Unix paths are expected for all OSes here
       ) as JsonObject | null;
     } catch (error) {
+      assertError(error);
       if (error.message !== 'type Config not found') {
         throw error;
       }
diff --git a/packages/config-loader/src/lib/transform/apply.ts b/packages/config-loader/src/lib/transform/apply.ts
index 690d280266..091f9c23c5 100644
--- a/packages/config-loader/src/lib/transform/apply.ts
+++ b/packages/config-loader/src/lib/transform/apply.ts
@@ -15,6 +15,7 @@
  */
 
 import { JsonObject, JsonValue } from '@backstage/config';
+import { assertError } from '@backstage/errors';
 import { TransformFunc } from './types';
 import { isObject } from './utils';
 
@@ -46,6 +47,7 @@ export async function applyConfigTransforms(
           break;
         }
       } catch (error) {
+        assertError(error);
         throw new Error(`error at ${path}, ${error.message}`);
       }
     }
diff --git a/packages/config-loader/src/loader.ts b/packages/config-loader/src/loader.ts
index 315b44c4ee..4abcc2e314 100644
--- a/packages/config-loader/src/loader.ts
+++ b/packages/config-loader/src/loader.ts
@@ -19,6 +19,7 @@ import yaml from 'yaml';
 import chokidar from 'chokidar';
 import { resolve as resolvePath, dirname, isAbsolute, basename } from 'path';
 import { AppConfig } from '@backstage/config';
+import { ForwardedError } from '@backstage/errors';
 import {
   applyConfigTransforms,
   readEnvConfig,
@@ -114,9 +115,7 @@ export async function loadConfig(
   try {
     fileConfigs = await loadConfigFiles();
   } catch (error) {
-    throw new Error(
-      `Failed to read static configuration file, ${error.message}`,
-    );
+    throw new ForwardedError('Failed to read static configuration file', error);
   }
 
   const envConfigs = await readEnvConfig(process.env);
diff --git a/packages/core-app-api/src/apis/implementations/DiscoveryApi/UrlPatternDiscovery.test.ts b/packages/core-app-api/src/apis/implementations/DiscoveryApi/UrlPatternDiscovery.test.ts
index 9cd666e8a3..7fcbde97df 100644
--- a/packages/core-app-api/src/apis/implementations/DiscoveryApi/UrlPatternDiscovery.test.ts
+++ b/packages/core-app-api/src/apis/implementations/DiscoveryApi/UrlPatternDiscovery.test.ts
@@ -45,25 +45,25 @@ describe('UrlPatternDiscovery', () => {
   it('should validate that the pattern is a valid URL', () => {
     expect(() => {
       UrlPatternDiscovery.compile('example.com');
-    }).toThrow('Invalid discovery URL pattern, Invalid URL: example.com');
+    }).toThrow("Invalid discovery URL pattern, URL 'example.com' is invalid");
 
     expect(() => {
       UrlPatternDiscovery.compile('http://');
-    }).toThrow('Invalid discovery URL pattern, Invalid URL: http://');
+    }).toThrow("Invalid discovery URL pattern, URL 'http://' is invalid");
 
     expect(() => {
       UrlPatternDiscovery.compile('abc123');
-    }).toThrow('Invalid discovery URL pattern, Invalid URL: abc123');
+    }).toThrow("Invalid discovery URL pattern, URL 'abc123' is invalid");
 
     expect(() => {
       UrlPatternDiscovery.compile('http://example.com:{{pluginId}}');
     }).toThrow(
-      'Invalid discovery URL pattern, Invalid URL: http://example.com:pluginId',
+      "Invalid discovery URL pattern, URL 'http://example.com:pluginId' is invalid",
     );
 
     expect(() => {
       UrlPatternDiscovery.compile('/{{pluginId}}');
-    }).toThrow('Invalid discovery URL pattern, Invalid URL: /pluginId');
+    }).toThrow("Invalid discovery URL pattern, URL '/pluginId' is invalid");
 
     expect(() => {
       UrlPatternDiscovery.compile('http://localhost/{{pluginId}}?forbidden');
diff --git a/packages/core-app-api/src/apis/implementations/DiscoveryApi/UrlPatternDiscovery.ts b/packages/core-app-api/src/apis/implementations/DiscoveryApi/UrlPatternDiscovery.ts
index 81cc5a26b1..58e14c9f04 100644
--- a/packages/core-app-api/src/apis/implementations/DiscoveryApi/UrlPatternDiscovery.ts
+++ b/packages/core-app-api/src/apis/implementations/DiscoveryApi/UrlPatternDiscovery.ts
@@ -16,6 +16,8 @@
 
 import { DiscoveryApi } from '@backstage/core-plugin-api';
 
+const ERROR_PREFIX = 'Invalid discovery URL pattern,';
+
 /**
  * UrlPatternDiscovery is a lightweight DiscoveryApi implementation.
  * It uses a single template string to construct URLs for each plugin.
@@ -30,21 +32,22 @@ export class UrlPatternDiscovery implements DiscoveryApi {
    */
   static compile(pattern: string): UrlPatternDiscovery {
     const parts = pattern.split(/\{\{\s*pluginId\s*\}\}/);
+    const urlStr = parts.join('pluginId');
 
+    let url;
     try {
-      const urlStr = parts.join('pluginId');
-      const url = new URL(urlStr);
-      if (url.hash) {
-        throw new Error('URL must not have a hash');
-      }
-      if (url.search) {
-        throw new Error('URL must not have a query');
-      }
-      if (urlStr.endsWith('/')) {
-        throw new Error('URL must not end with a slash');
-      }
-    } catch (error) {
-      throw new Error(`Invalid discovery URL pattern, ${error.message}`);
+      url = new URL(urlStr);
+    } catch {
+      throw new Error(`${ERROR_PREFIX} URL '${urlStr}' is invalid`);
+    }
+    if (url.hash) {
+      throw new Error(`${ERROR_PREFIX} URL must not have a hash`);
+    }
+    if (url.search) {
+      throw new Error(`${ERROR_PREFIX} URL must not have a query`);
+    }
+    if (urlStr.endsWith('/')) {
+      throw new Error(`${ERROR_PREFIX} URL must not end with a slash`);
     }
 
     return new UrlPatternDiscovery(parts);
diff --git a/packages/core-app-api/src/routing/RoutingProvider.test.tsx b/packages/core-app-api/src/routing/RoutingProvider.test.tsx
index 12d9e9ee33..fbdd34ae68 100644
--- a/packages/core-app-api/src/routing/RoutingProvider.test.tsx
+++ b/packages/core-app-api/src/routing/RoutingProvider.test.tsx
@@ -83,7 +83,7 @@ const MockRouteSource = <T extends { [name in string]: string }>(props: {
   } catch (ex) {
     return (
       <div>
-        Error at {props.name}: {ex.message}
+        Error at {props.name}, {String(ex)}
       </div>
     );
   }
@@ -293,12 +293,12 @@ describe('discovery', () => {
 
     expect(
       rendered.getByText(
-        `Error at outsideWithParams: Cannot route to ${ref3} with parent ${ref5} as it has parameters`,
+        `Error at outsideWithParams, Error: Cannot route to ${ref3} with parent ${ref5} as it has parameters`,
       ),
     ).toBeInTheDocument();
     expect(
       rendered.getByText(
-        `Error at outsideNoParams: Cannot route to ${ref3} with parent ${ref5} as it has parameters`,
+        `Error at outsideNoParams, Error: Cannot route to ${ref3} with parent ${ref5} as it has parameters`,
       ),
     ).toBeInTheDocument();
   });
diff --git a/packages/core-components/src/components/OAuthRequestDialog/LoginRequestListItem.tsx b/packages/core-components/src/components/OAuthRequestDialog/LoginRequestListItem.tsx
index b911a9a1d9..ef0d2373e4 100644
--- a/packages/core-components/src/components/OAuthRequestDialog/LoginRequestListItem.tsx
+++ b/packages/core-components/src/components/OAuthRequestDialog/LoginRequestListItem.tsx
@@ -21,6 +21,7 @@ import ListItemText from '@material-ui/core/ListItemText';
 import Typography from '@material-ui/core/Typography';
 import Button from '@material-ui/core/Button';
 import React, { useState } from 'react';
+import { isError } from '@backstage/errors';
 import { PendingAuthRequest } from '@backstage/core-plugin-api';
 
 export type LoginRequestListItemClassKey = 'root';
@@ -42,14 +43,14 @@ type RowProps = {
 
 const LoginRequestListItem = ({ request, busy, setBusy }: RowProps) => {
   const classes = useItemStyles();
-  const [error, setError] = useState<Error>();
+  const [error, setError] = useState<string>();
 
   const handleContinue = async () => {
     setBusy(true);
     try {
       await request.trigger();
     } catch (e) {
-      setError(e);
+      setError(isError(e) ? e.message : 'An unspecified error occurred');
     } finally {
       setBusy(false);
     }
@@ -64,13 +65,7 @@ const LoginRequestListItem = ({ request, busy, setBusy }: RowProps) => {
       </ListItemAvatar>
       <ListItemText
         primary={request.provider.title}
-        secondary={
-          error && (
-            <Typography color="error">
-              {error.message || 'An unspecified error occurred'}
-            </Typography>
-          )
-        }
+        secondary={error && <Typography color="error">{error}</Typography>}
       />
       <Button color="primary" variant="contained" onClick={handleContinue}>
         Log in
diff --git a/packages/core-components/src/layout/SignInPage/auth0Provider.tsx b/packages/core-components/src/layout/SignInPage/auth0Provider.tsx
index 19836827c9..e1372a2362 100644
--- a/packages/core-components/src/layout/SignInPage/auth0Provider.tsx
+++ b/packages/core-components/src/layout/SignInPage/auth0Provider.tsx
@@ -25,6 +25,7 @@ import {
   auth0AuthApiRef,
   errorApiRef,
 } from '@backstage/core-plugin-api';
+import { ForwardedError } from '@backstage/errors';
 
 const Component: ProviderComponent = ({ onResult }) => {
   const auth0AuthApi = useApi(auth0AuthApiRef);
@@ -53,7 +54,7 @@ const Component: ProviderComponent = ({ onResult }) => {
         },
       });
     } catch (error) {
-      errorApi.post(error);
+      errorApi.post(new ForwardedError('Auth0 login failed', error));
     }
   };
 
diff --git a/packages/core-components/src/layout/SignInPage/commonProvider.tsx b/packages/core-components/src/layout/SignInPage/commonProvider.tsx
index 8df5faf34e..103050a2d9 100644
--- a/packages/core-components/src/layout/SignInPage/commonProvider.tsx
+++ b/packages/core-components/src/layout/SignInPage/commonProvider.tsx
@@ -26,6 +26,7 @@ import {
 } from './types';
 import { useApi, errorApiRef } from '@backstage/core-plugin-api';
 import { GridItem } from './styles';
+import { ForwardedError } from '@backstage/errors';
 
 const Component: ProviderComponent = ({ config, onResult }) => {
   const { apiRef, title, message } = config as SignInProviderConfig;
@@ -55,7 +56,7 @@ const Component: ProviderComponent = ({ config, onResult }) => {
         },
       });
     } catch (error) {
-      errorApi.post(error);
+      errorApi.post(new ForwardedError('Login failed', error));
     }
   };
 
diff --git a/packages/core-plugin-api/src/extensions/extensions.tsx b/packages/core-plugin-api/src/extensions/extensions.tsx
index 4aff027f31..2eb5275c66 100644
--- a/packages/core-plugin-api/src/extensions/extensions.tsx
+++ b/packages/core-plugin-api/src/extensions/extensions.tsx
@@ -51,12 +51,18 @@ export function createRoutableExtension<
               try {
                 useRouteRef(mountPoint);
               } catch (error) {
-                if (error?.message.startsWith('No path for ')) {
-                  throw new Error(
-                    `Routable extension component with mount point ${mountPoint} was not discovered in the app element tree. ` +
-                      'Routable extension components may not be rendered by other components and must be ' +
-                      'directly available as an element within the App provider component.',
-                  );
+                if (typeof error === 'object' && error !== null) {
+                  const { message } = error as { message?: unknown };
+                  if (
+                    typeof message === 'string' &&
+                    message.startsWith('No path for ')
+                  ) {
+                    throw new Error(
+                      `Routable extension component with mount point ${mountPoint} was not discovered in the app element tree. ` +
+                        'Routable extension components may not be rendered by other components and must be ' +
+                        'directly available as an element within the App provider component.',
+                    );
+                  }
                 }
                 throw error;
               }
diff --git a/packages/create-app/src/createApp.ts b/packages/create-app/src/createApp.ts
index 1da3139f41..562ebf0e22 100644
--- a/packages/create-app/src/createApp.ts
+++ b/packages/create-app/src/createApp.ts
@@ -45,9 +45,7 @@ async function createTemporaryAppFolder(tempDir: string) {
     try {
       await fs.mkdir(tempDir);
     } catch (error) {
-      throw new Error(
-        `Failed to create temporary app directory: ${error.message}`,
-      );
+      throw new Error(`Failed to create temporary app directory, ${error}`);
     }
   });
 }
@@ -156,7 +154,7 @@ export default async (cmd: Command): Promise<void> => {
     Task.log();
     Task.exit();
   } catch (error) {
-    Task.error(error.message);
+    Task.error(String(error));
 
     Task.log('It seems that something went wrong when creating the app 🤔');
     Task.log('We are going to clean up, and then you can try again.');
diff --git a/packages/e2e-test/package.json b/packages/e2e-test/package.json
index 900fbba136..e783fa1de6 100644
--- a/packages/e2e-test/package.json
+++ b/packages/e2e-test/package.json
@@ -25,6 +25,7 @@
   },
   "devDependencies": {
     "@backstage/cli-common": "^0.1.1",
+    "@backstage/errors": "^0.1.2",
     "@types/fs-extra": "^9.0.1",
     "@types/node": "^14.14.32",
     "chalk": "^4.0.0",
diff --git a/packages/e2e-test/src/lib/helpers.ts b/packages/e2e-test/src/lib/helpers.ts
index db6c31512c..f326311f07 100644
--- a/packages/e2e-test/src/lib/helpers.ts
+++ b/packages/e2e-test/src/lib/helpers.ts
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+import { assertError } from '@backstage/errors';
 import {
   spawn,
   execFile as execFileCb,
@@ -66,11 +67,12 @@ export async function runPlain(cmd: string[], options?: SpawnOptions) {
     });
     return stdout.trim();
   } catch (error) {
+    assertError(error);
     if (error.stdout) {
-      process.stdout.write(error.stdout);
+      process.stdout.write(error.stdout as Buffer);
     }
     if (error.stderr) {
-      process.stderr.write(error.stderr);
+      process.stderr.write(error.stderr as Buffer);
     }
     throw error;
   }
@@ -147,6 +149,7 @@ export async function waitForPageWithText(
       );
       break;
     } catch (error) {
+      assertError(error);
       if (error.message.match(EXPECTED_LOAD_ERRORS)) {
         loadAttempts++;
         if (loadAttempts >= maxLoadAttempts) {
diff --git a/packages/techdocs-common/src/stages/generate/helpers.ts b/packages/techdocs-common/src/stages/generate/helpers.ts
index 0ac05e7dd2..94746c1aaa 100644
--- a/packages/techdocs-common/src/stages/generate/helpers.ts
+++ b/packages/techdocs-common/src/stages/generate/helpers.ts
@@ -16,6 +16,7 @@
 
 import { isChildPath } from '@backstage/backend-common';
 import { Entity } from '@backstage/catalog-model';
+import { assertError, ForwardedError } from '@backstage/errors';
 import { ScmIntegrationRegistry } from '@backstage/integration';
 import { spawn } from 'child_process';
 import fs from 'fs-extra';
@@ -155,8 +156,9 @@ export const getMkdocsYml = async (
       mkdocsYmlPath = path.join(inputDir, 'mkdocs.yml');
       mkdocsYmlFileString = await fs.readFile(mkdocsYmlPath, 'utf8');
     } catch (error) {
-      throw new Error(
-        `Could not read MkDocs YAML config file mkdocs.yml or mkdocs.yaml for validation: ${error.message}`,
+      throw new ForwardedError(
+        'Could not read MkDocs YAML config file mkdocs.yml or mkdocs.yaml for validation',
+        error,
       );
     }
   }
@@ -225,6 +227,7 @@ export const patchMkdocsYmlPreBuild = async (
   try {
     mkdocsYmlFileString = await fs.readFile(mkdocsYmlPath, 'utf8');
   } catch (error) {
+    assertError(error);
     logger.warn(
       `Could not read MkDocs YAML config file ${mkdocsYmlPath} before running the generator: ${error.message}`,
     );
@@ -241,6 +244,7 @@ export const patchMkdocsYmlPreBuild = async (
       throw new Error('Bad YAML format.');
     }
   } catch (error) {
+    assertError(error);
     logger.warn(
       `Error in parsing YAML at ${mkdocsYmlPath} before running the generator. ${error.message}`,
     );
@@ -279,6 +283,7 @@ export const patchMkdocsYmlPreBuild = async (
       );
     }
   } catch (error) {
+    assertError(error);
     logger.warn(
       `Could not write to ${mkdocsYmlPath} after updating it before running the generator. ${error.message}`,
     );
@@ -307,6 +312,7 @@ export const addBuildTimestampMetadata = async (
   try {
     json = await fs.readJson(techdocsMetadataPath);
   } catch (err) {
+    assertError(err);
     const message = `Invalid JSON at ${techdocsMetadataPath} with error ${err.message}`;
     logger.error(message);
     throw new Error(message);
diff --git a/packages/techdocs-common/src/stages/generate/techdocs.ts b/packages/techdocs-common/src/stages/generate/techdocs.ts
index d5d4584c34..82515fd28d 100644
--- a/packages/techdocs-common/src/stages/generate/techdocs.ts
+++ b/packages/techdocs-common/src/stages/generate/techdocs.ts
@@ -36,6 +36,7 @@ import {
   GeneratorRunInType,
   GeneratorRunOptions,
 } from './types';
+import { ForwardedError } from '@backstage/errors';
 
 export class TechdocsGenerator implements GeneratorBase {
   /**
@@ -151,8 +152,9 @@ export class TechdocsGenerator implements GeneratorBase {
       this.logger.debug(
         `Failed to generate docs from ${inputDir} into ${outputDir}`,
       );
-      throw new Error(
-        `Failed to generate docs from ${inputDir} into ${outputDir} with error ${error.message}`,
+      throw new ForwardedError(
+        'Failed to generate docs from ${inputDir} into ${outputDir}',
+        error,
       );
     }
 
diff --git a/packages/techdocs-common/src/stages/prepare/url.ts b/packages/techdocs-common/src/stages/prepare/url.ts
index 6e2750ee4d..cd4a8860e4 100644
--- a/packages/techdocs-common/src/stages/prepare/url.ts
+++ b/packages/techdocs-common/src/stages/prepare/url.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { NotModifiedError } from '@backstage/errors';
+import { assertError } from '@backstage/errors';
 import { UrlReader } from '@backstage/backend-common';
 import { Entity } from '@backstage/catalog-model';
 import { Logger } from 'winston';
@@ -40,8 +40,9 @@ export class UrlPreparer implements PreparerBase {
         logger: this.logger,
       });
     } catch (error) {
+      assertError(error);
       // NotModifiedError means that etag based cache is still valid.
-      if (error instanceof NotModifiedError) {
+      if (error.name === 'NotModifiedError') {
         this.logger.debug(`Cache is valid for etag ${options?.etag}`);
       } else {
         this.logger.debug(
diff --git a/packages/techdocs-common/src/stages/publish/awsS3.test.ts b/packages/techdocs-common/src/stages/publish/awsS3.test.ts
index 35bc80438b..d5ff1f4117 100644
--- a/packages/techdocs-common/src/stages/publish/awsS3.test.ts
+++ b/packages/techdocs-common/src/stages/publish/awsS3.test.ts
@@ -286,7 +286,7 @@ describe('AwsS3Publish', () => {
       const fails = publisher.fetchTechDocsMetadata(invalidEntityName);
 
       await expect(fails).rejects.toMatchObject({
-        message: `TechDocs metadata fetch failed, The file ${techDocsMetadaFilePath} does not exist!`,
+        message: `TechDocs metadata fetch failed; caused by Error: The file ${techDocsMetadaFilePath} does not exist!`,
       });
     });
   });
diff --git a/packages/techdocs-common/src/stages/publish/awsS3.ts b/packages/techdocs-common/src/stages/publish/awsS3.ts
index f2e1b867ec..ee48db575f 100644
--- a/packages/techdocs-common/src/stages/publish/awsS3.ts
+++ b/packages/techdocs-common/src/stages/publish/awsS3.ts
@@ -15,6 +15,7 @@
  */
 import { Entity, EntityName } from '@backstage/catalog-model';
 import { Config } from '@backstage/config';
+import { assertError, ForwardedError } from '@backstage/errors';
 import aws, { Credentials } from 'aws-sdk';
 import { ListObjectsV2Output } from 'aws-sdk/clients/s3';
 import { CredentialsOptions } from 'aws-sdk/lib/credentials';
@@ -49,7 +50,7 @@ const streamToBuffer = (stream: Readable): Promise<Buffer> => {
       stream.on('error', reject);
       stream.on('end', () => resolve(Buffer.concat(chunks)));
     } catch (e) {
-      throw new Error(`Unable to parse the response data ${e.message}`);
+      throw new ForwardedError('Unable to parse the response data', e);
     }
   });
 };
@@ -204,6 +205,7 @@ export class AwsS3Publish implements PublisherBase {
         prefix: remoteFolder,
       });
     } catch (e) {
+      assertError(e);
       this.logger.error(
         `Unable to list files for Entity ${entity.metadata.name}: ${e.message}`,
       );
@@ -312,12 +314,13 @@ export class AwsS3Publish implements PublisherBase {
 
           resolve(techdocsMetadata);
         } catch (err) {
+          assertError(err);
           this.logger.error(err.message);
           reject(new Error(err.message));
         }
       });
     } catch (e) {
-      throw new Error(`TechDocs metadata fetch failed, ${e.message}`);
+      throw new ForwardedError('TechDocs metadata fetch failed', e);
     }
   }
 
@@ -351,6 +354,7 @@ export class AwsS3Publish implements PublisherBase {
 
         res.send(await streamToBuffer(stream));
       } catch (err) {
+        assertError(err);
         this.logger.warn(
           `TechDocs S3 router failed to serve static files from bucket ${this.bucketName} at key ${filePath}: ${err.message}`,
         );
@@ -396,6 +400,7 @@ export class AwsS3Publish implements PublisherBase {
           try {
             newPath = lowerCaseEntityTripletInStoragePath(file);
           } catch (e) {
+            assertError(e);
             this.logger.warn(e.message);
             return;
           }
@@ -424,6 +429,7 @@ export class AwsS3Publish implements PublisherBase {
                 .promise();
             }
           } catch (e) {
+            assertError(e);
             this.logger.warn(`Unable to migrate ${file}: ${e.message}`);
           }
         }, f),
diff --git a/packages/techdocs-common/src/stages/publish/azureBlobStorage.test.ts b/packages/techdocs-common/src/stages/publish/azureBlobStorage.test.ts
index cace6caae8..c3d9705ea9 100644
--- a/packages/techdocs-common/src/stages/publish/azureBlobStorage.test.ts
+++ b/packages/techdocs-common/src/stages/publish/azureBlobStorage.test.ts
@@ -201,7 +201,7 @@ describe('AzureBlobStoragePublish', () => {
       let error;
       try {
         await publisher.publish({ entity, directory });
-      } catch (e) {
+      } catch (e: any) {
         error = e;
       }
 
@@ -305,7 +305,7 @@ describe('AzureBlobStoragePublish', () => {
       const fails = publisher.fetchTechDocsMetadata(invalidEntityName);
 
       await expect(fails).rejects.toMatchObject({
-        message: `TechDocs metadata fetch failed, The file ${techDocsMetadaFilePath} does not exist!`,
+        message: `TechDocs metadata fetch failed; caused by Error: The file ${techDocsMetadaFilePath} does not exist!`,
       });
     });
   });
diff --git a/packages/techdocs-common/src/stages/publish/azureBlobStorage.ts b/packages/techdocs-common/src/stages/publish/azureBlobStorage.ts
index 60a93ea520..f1d60f709a 100644
--- a/packages/techdocs-common/src/stages/publish/azureBlobStorage.ts
+++ b/packages/techdocs-common/src/stages/publish/azureBlobStorage.ts
@@ -21,6 +21,7 @@ import {
 } from '@azure/storage-blob';
 import { Entity, EntityName } from '@backstage/catalog-model';
 import { Config } from '@backstage/config';
+import { assertError, ForwardedError } from '@backstage/errors';
 import express from 'express';
 import JSON5 from 'json5';
 import limiterFactory from 'p-limit';
@@ -132,6 +133,7 @@ export class AzureBlobStoragePublish implements PublisherBase {
         );
       }
     } catch (e) {
+      assertError(e);
       this.logger.error(`from Azure Blob Storage client library: ${e.message}`);
     }
 
@@ -165,6 +167,7 @@ export class AzureBlobStoragePublish implements PublisherBase {
         maxPageSize: BATCH_CONCURRENCY,
       });
     } catch (e) {
+      assertError(e);
       this.logger.error(
         `Unable to list files for Entity ${entity.metadata.name}: ${e.message}`,
       );
@@ -307,7 +310,7 @@ export class AzureBlobStoragePublish implements PublisherBase {
       );
       return techdocsMetadata;
     } catch (e) {
-      throw new Error(`TechDocs metadata fetch failed, ${e.message}`);
+      throw new ForwardedError('TechDocs metadata fetch failed', e);
     }
   }
 
@@ -386,6 +389,7 @@ export class AzureBlobStoragePublish implements PublisherBase {
     try {
       newPath = lowerCaseEntityTripletInStoragePath(originalPath);
     } catch (e) {
+      assertError(e);
       this.logger.warn(e.message);
       return;
     }
@@ -395,6 +399,7 @@ export class AzureBlobStoragePublish implements PublisherBase {
       this.logger.verbose(`Migrating ${originalPath}`);
       await this.renameBlob(originalPath, newPath, removeOriginal);
     } catch (e) {
+      assertError(e);
       this.logger.warn(`Unable to migrate ${originalPath}: ${e.message}`);
     }
   }
diff --git a/packages/techdocs-common/src/stages/publish/googleStorage.ts b/packages/techdocs-common/src/stages/publish/googleStorage.ts
index 81bbd556eb..dcce1b8ee9 100644
--- a/packages/techdocs-common/src/stages/publish/googleStorage.ts
+++ b/packages/techdocs-common/src/stages/publish/googleStorage.ts
@@ -15,6 +15,7 @@
  */
 import { Entity, EntityName } from '@backstage/catalog-model';
 import { Config } from '@backstage/config';
+import { assertError } from '@backstage/errors';
 import { File, FileExistsResponse, Storage } from '@google-cloud/storage';
 import express from 'express';
 import JSON5 from 'json5';
@@ -112,6 +113,7 @@ export class GoogleGCSPublish implements PublisherBase {
         isAvailable: true,
       };
     } catch (err) {
+      assertError(err);
       this.logger.error(
         `Could not retrieve metadata about the GCS bucket ${this.bucketName}. ` +
           'Make sure the bucket exists. Also make sure that authentication is setup either by explicitly defining ' +
@@ -142,6 +144,7 @@ export class GoogleGCSPublish implements PublisherBase {
       );
       existingFiles = await this.getFilesForFolder(remoteFolder);
     } catch (e) {
+      assertError(e);
       this.logger.error(
         `Unable to list files for Entity ${entity.metadata.name}: ${e.message}`,
       );
diff --git a/packages/techdocs-common/src/stages/publish/local.ts b/packages/techdocs-common/src/stages/publish/local.ts
index c547b65406..de0072de7a 100644
--- a/packages/techdocs-common/src/stages/publish/local.ts
+++ b/packages/techdocs-common/src/stages/publish/local.ts
@@ -37,6 +37,7 @@ import {
   getHeadersForFileExtension,
   lowerCaseEntityTripletInStoragePath,
 } from './helpers';
+import { assertError } from '@backstage/errors';
 
 // TODO: Use a more persistent storage than node_modules or /tmp directory.
 // Make it configurable with techdocs.publisher.local.publishDirectory
@@ -134,6 +135,7 @@ export class LocalPublish implements PublisherBase {
     try {
       return await fs.readJson(metadataPath);
     } catch (err) {
+      assertError(err);
       this.logger.error(
         `Unable to read techdocs_metadata.json at ${metadataPath}. Error: ${err}`,
       );
diff --git a/packages/techdocs-common/src/stages/publish/migrations/GoogleMigration.ts b/packages/techdocs-common/src/stages/publish/migrations/GoogleMigration.ts
index 192cefbfe2..69d5353f9f 100644
--- a/packages/techdocs-common/src/stages/publish/migrations/GoogleMigration.ts
+++ b/packages/techdocs-common/src/stages/publish/migrations/GoogleMigration.ts
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+import { assertError } from '@backstage/errors';
 import { File } from '@google-cloud/storage';
 import { Writable } from 'stream';
 import { Logger } from 'winston';
@@ -42,6 +43,7 @@ export class MigrateWriteStream extends Writable {
     try {
       newFile = lowerCaseEntityTripletInStoragePath(file.name);
     } catch (e) {
+      assertError(e);
       this.logger.warn(e.message);
       next();
       return;
diff --git a/packages/techdocs-common/src/stages/publish/openStackSwift.ts b/packages/techdocs-common/src/stages/publish/openStackSwift.ts
index e224fbdbaf..51e7b76406 100644
--- a/packages/techdocs-common/src/stages/publish/openStackSwift.ts
+++ b/packages/techdocs-common/src/stages/publish/openStackSwift.ts
@@ -31,6 +31,7 @@ import {
   ReadinessResponse,
   TechDocsMetadata,
 } from './types';
+import { assertError, ForwardedError } from '@backstage/errors';
 
 const streamToBuffer = (stream: Stream | Readable): Promise<Buffer> => {
   return new Promise((resolve, reject) => {
@@ -40,7 +41,7 @@ const streamToBuffer = (stream: Stream | Readable): Promise<Buffer> => {
       stream.on('error', reject);
       stream.on('end', () => resolve(Buffer.concat(chunks)));
     } catch (e) {
-      throw new Error(`Unable to parse the response data ${e.message}`);
+      throw new ForwardedError('Unable to parse the response data', e);
     }
   });
 };
@@ -118,6 +119,7 @@ export class OpenStackSwiftPublish implements PublisherBase {
         isAvailable: false,
       };
     } catch (err) {
+      assertError(err);
       this.logger.error(`from OpenStack client library: ${err.message}`);
       return {
         isAvailable: false,
@@ -203,6 +205,7 @@ export class OpenStackSwiftPublish implements PublisherBase {
 
           resolve(techdocsMetadata);
         } catch (err) {
+          assertError(err);
           this.logger.error(err.message);
           reject(new Error(err.message));
         }
@@ -245,6 +248,7 @@ export class OpenStackSwiftPublish implements PublisherBase {
 
           res.send(await streamToBuffer(stream));
         } catch (err) {
+          assertError(err);
           this.logger.warn(
             `TechDocs OpenStack swift router failed to serve content from container ${this.containerName} at path ${filePath}: ${err.message}`,
           );
@@ -276,6 +280,7 @@ export class OpenStackSwiftPublish implements PublisherBase {
       }
       return false;
     } catch (err) {
+      assertError(err);
       this.logger.warn(err.message);
       return false;
     }
diff --git a/plugins/auth-backend/src/lib/oauth/OAuthAdapter.ts b/plugins/auth-backend/src/lib/oauth/OAuthAdapter.ts
index 1f424febf5..a5128711bc 100644
--- a/plugins/auth-backend/src/lib/oauth/OAuthAdapter.ts
+++ b/plugins/auth-backend/src/lib/oauth/OAuthAdapter.ts
@@ -22,7 +22,7 @@ import {
   BackstageIdentity,
   AuthProviderConfig,
 } from '../../providers/types';
-import { InputError, NotAllowedError } from '@backstage/errors';
+import { InputError, isError, NotAllowedError } from '@backstage/errors';
 import { TokenIssuer } from '../../identity/types';
 import { readState, verifyNonce } from './helpers';
 import { postMessageResponse, ensuresXRequestedWith } from '../flow';
@@ -153,13 +153,13 @@ export class OAuthAdapter implements AuthProviderRouteHandlers {
         response,
       });
     } catch (error) {
+      const { name, message } = isError(error)
+        ? error
+        : new Error('Encountered invalid error'); // Being a bit safe and not forwarding the bad value
       // post error message back to popup if failure
       return postMessageResponse(res, appOrigin, {
         type: 'authorization_response',
-        error: {
-          name: error.name,
-          message: error.message,
-        },
+        error: { name, message },
       });
     }
   }
@@ -220,7 +220,7 @@ export class OAuthAdapter implements AuthProviderRouteHandlers {
 
       res.status(200).json(response);
     } catch (error) {
-      res.status(401).send(`${error.message}`);
+      res.status(401).send(String(error));
     }
   }
 
diff --git a/plugins/auth-backend/src/providers/saml/provider.ts b/plugins/auth-backend/src/providers/saml/provider.ts
index e0e5fc8c8f..07fc77e4f7 100644
--- a/plugins/auth-backend/src/providers/saml/provider.ts
+++ b/plugins/auth-backend/src/providers/saml/provider.ts
@@ -29,6 +29,7 @@ import {
 import { AuthProviderRouteHandlers, AuthProviderFactory } from '../types';
 import { postMessageResponse } from '../../lib/flow';
 import { TokenIssuer } from '../../identity/types';
+import { isError } from '@backstage/errors';
 
 type SamlInfo = {
   fullProfile: any;
@@ -93,12 +94,12 @@ export class SamlAuthProvider implements AuthProviderRouteHandlers {
         },
       });
     } catch (error) {
+      const { name, message } = isError(error)
+        ? error
+        : new Error('Encountered invalid error'); // Being a bit safe and not forwarding the bad value
       return postMessageResponse(res, this.appUrl, {
         type: 'authorization_response',
-        error: {
-          name: error.name,
-          message: error.message,
-        },
+        error: { name, message },
       });
     }
   }
diff --git a/plugins/auth-backend/src/service/router.ts b/plugins/auth-backend/src/service/router.ts
index 423975aa75..90678da4e4 100644
--- a/plugins/auth-backend/src/service/router.ts
+++ b/plugins/auth-backend/src/service/router.ts
@@ -26,7 +26,7 @@ import {
   PluginDatabaseManager,
   PluginEndpointDiscovery,
 } from '@backstage/backend-common';
-import { NotFoundError } from '@backstage/errors';
+import { assertError, NotFoundError } from '@backstage/errors';
 import { CatalogClient } from '@backstage/catalog-client';
 import { Config } from '@backstage/config';
 import { createOidcRouter, DatabaseKeyStore, TokenFactory } from '../identity';
@@ -121,6 +121,7 @@ export async function createRouter({
 
         router.use(`/${providerId}`, r);
       } catch (e) {
+        assertError(e);
         if (process.env.NODE_ENV !== 'development') {
           throw new Error(
             `Failed to initialize ${providerId} auth provider, ${e.message}`,
diff --git a/plugins/catalog-backend-module-ldap/package.json b/plugins/catalog-backend-module-ldap/package.json
index 8e68ccd2e3..9884a55bcc 100644
--- a/plugins/catalog-backend-module-ldap/package.json
+++ b/plugins/catalog-backend-module-ldap/package.json
@@ -31,6 +31,7 @@
   "dependencies": {
     "@backstage/catalog-model": "^0.9.4",
     "@backstage/config": "^0.1.10",
+    "@backstage/errors": "^0.1.2",
     "@backstage/plugin-catalog-backend": "^0.17.0",
     "@types/ldapjs": "^2.2.0",
     "ldapjs": "^2.2.0",
diff --git a/plugins/catalog-backend-module-ldap/src/ldap/client.ts b/plugins/catalog-backend-module-ldap/src/ldap/client.ts
index 048aa40dc1..553081f4b0 100644
--- a/plugins/catalog-backend-module-ldap/src/ldap/client.ts
+++ b/plugins/catalog-backend-module-ldap/src/ldap/client.ts
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+import { ForwardedError } from '@backstage/errors';
 import ldap, { Client, SearchEntry, SearchOptions } from 'ldapjs';
 import { Logger } from 'winston';
 import { BindConfig } from './config';
@@ -120,7 +121,7 @@ export class LdapClient {
         clearInterval(logInterval);
       });
     } catch (e) {
-      throw new Error(`LDAP search at DN "${dn}" failed, ${e.message}`);
+      throw new ForwardedError(`LDAP search at DN "${dn}" failed`, e);
     }
   }
 
@@ -167,7 +168,7 @@ export class LdapClient {
         });
       });
     } catch (e) {
-      throw new Error(`LDAP search at DN "${dn}" failed, ${e.message}`);
+      throw new ForwardedError(`LDAP search at DN "${dn}" failed`, e);
     }
   }
 
diff --git a/plugins/catalog-backend/src/database/DefaultProcessingDatabase.ts b/plugins/catalog-backend/src/database/DefaultProcessingDatabase.ts
index 0b9d3653a0..f2f478c481 100644
--- a/plugins/catalog-backend/src/database/DefaultProcessingDatabase.ts
+++ b/plugins/catalog-backend/src/database/DefaultProcessingDatabase.ts
@@ -15,7 +15,7 @@
  */
 
 import { Entity, stringifyEntityRef } from '@backstage/catalog-model';
-import { ConflictError, NotFoundError } from '@backstage/errors';
+import { ConflictError, isError, NotFoundError } from '@backstage/errors';
 import { Knex } from 'knex';
 import lodash from 'lodash';
 import { v4 as uuid } from 'uuid';
@@ -550,7 +550,10 @@ export class DefaultProcessingDatabase implements ProcessingDatabase {
       return result.rowCount === 1 || result.length === 1;
     } catch (error) {
       // SQLite reached this rather than the rowCount check above
-      if (error.message.includes('UNIQUE constraint failed')) {
+      if (
+        isError(error) &&
+        error.message.includes('UNIQUE constraint failed')
+      ) {
         return false;
       }
       throw error;
diff --git a/plugins/catalog-backend/src/ingestion/processors/AwsS3DiscoveryProcessor.ts b/plugins/catalog-backend/src/ingestion/processors/AwsS3DiscoveryProcessor.ts
index c394e9b047..63bc45726d 100644
--- a/plugins/catalog-backend/src/ingestion/processors/AwsS3DiscoveryProcessor.ts
+++ b/plugins/catalog-backend/src/ingestion/processors/AwsS3DiscoveryProcessor.ts
@@ -16,6 +16,7 @@
 
 import { UrlReader } from '@backstage/backend-common';
 import { LocationSpec } from '@backstage/catalog-model';
+import { isError } from '@backstage/errors';
 import limiterFactory from 'p-limit';
 import * as result from './results';
 import {
@@ -50,7 +51,7 @@ export class AwsS3DiscoveryProcessor implements CatalogProcessor {
     } catch (error) {
       const message = `Unable to read ${location.type}, ${error}`;
 
-      if (error.name === 'NotFoundError') {
+      if (isError(error) && error.name === 'NotFoundError') {
         if (!optional) {
           emit(result.notFoundError(location, message));
         }
diff --git a/plugins/catalog-backend/src/legacy/ingestion/LocationReaders.ts b/plugins/catalog-backend/src/legacy/ingestion/LocationReaders.ts
index 91902ce5be..04347615e5 100644
--- a/plugins/catalog-backend/src/legacy/ingestion/LocationReaders.ts
+++ b/plugins/catalog-backend/src/legacy/ingestion/LocationReaders.ts
@@ -255,7 +255,7 @@ export class LocationReaders implements LocationReader {
       const message = `Policy check failed while analyzing entity ${kind}:${namespace}/${name} at ${stringifyLocationReference(
         item.location,
       )}, ${e}`;
-      emit(result.inputError(item.location, e.message));
+      emit(result.inputError(item.location, message));
       logger.warn(message);
       return undefined;
     }
diff --git a/plugins/catalog-backend/src/processing/DefaultCatalogProcessingEngine.ts b/plugins/catalog-backend/src/processing/DefaultCatalogProcessingEngine.ts
index 59cd4d94ae..1ce32a01e1 100644
--- a/plugins/catalog-backend/src/processing/DefaultCatalogProcessingEngine.ts
+++ b/plugins/catalog-backend/src/processing/DefaultCatalogProcessingEngine.ts
@@ -19,7 +19,7 @@ import {
   entityEnvelopeSchemaValidator,
   stringifyEntityRef,
 } from '@backstage/catalog-model';
-import { serializeError } from '@backstage/errors';
+import { assertError, serializeError } from '@backstage/errors';
 import { Hash } from 'crypto';
 import stableStringify from 'fast-json-stable-stringify';
 import { Logger } from 'winston';
@@ -257,6 +257,7 @@ export class DefaultCatalogProcessingEngine implements CatalogProcessingEngine {
 
           track.markSuccessfulWithChanges(setOfThingsToStitch.size);
         } catch (error) {
+          assertError(error);
           track.markFailed(error);
         }
       },
diff --git a/plugins/catalog-backend/src/processing/DefaultCatalogProcessingOrchestrator.ts b/plugins/catalog-backend/src/processing/DefaultCatalogProcessingOrchestrator.ts
index e973dcbf0c..d3ec162216 100644
--- a/plugins/catalog-backend/src/processing/DefaultCatalogProcessingOrchestrator.ts
+++ b/plugins/catalog-backend/src/processing/DefaultCatalogProcessingOrchestrator.ts
@@ -23,7 +23,12 @@ import {
   stringifyEntityRef,
   stringifyLocationReference,
 } from '@backstage/catalog-model';
-import { ConflictError, InputError, NotAllowedError } from '@backstage/errors';
+import {
+  assertError,
+  ConflictError,
+  InputError,
+  NotAllowedError,
+} from '@backstage/errors';
 import { JsonValue } from '@backstage/config';
 import { ScmIntegrationRegistry } from '@backstage/integration';
 import path from 'path';
@@ -160,6 +165,7 @@ export class DefaultCatalogProcessingOrchestrator
         ok: collectorResults.errors.length === 0,
       };
     } catch (error) {
+      assertError(error);
       return {
         ok: false,
         errors: collector.results().errors.concat(error),
diff --git a/plugins/catalog-backend/src/processing/ProcessorOutputCollector.ts b/plugins/catalog-backend/src/processing/ProcessorOutputCollector.ts
index dfaa25418b..436038db66 100644
--- a/plugins/catalog-backend/src/processing/ProcessorOutputCollector.ts
+++ b/plugins/catalog-backend/src/processing/ProcessorOutputCollector.ts
@@ -21,6 +21,7 @@ import {
   ORIGIN_LOCATION_ANNOTATION,
   stringifyLocationReference,
 } from '@backstage/catalog-model';
+import { assertError } from '@backstage/errors';
 import { Logger } from 'winston';
 import { CatalogProcessorResult } from '../ingestion';
 import { locationSpecToLocationEntity } from '../util/conversion';
@@ -73,6 +74,7 @@ export class ProcessorOutputCollector {
       try {
         entity = validateEntityEnvelope(i.entity);
       } catch (e) {
+        assertError(e);
         this.logger.debug(`Envelope validation failed at ${i.location}, ${e}`);
         this.errors.push(e);
         return;
diff --git a/plugins/catalog-import/package.json b/plugins/catalog-import/package.json
index 09b59f9d86..d443d3cb22 100644
--- a/plugins/catalog-import/package.json
+++ b/plugins/catalog-import/package.json
@@ -35,6 +35,7 @@
     "@backstage/catalog-model": "^0.9.4",
     "@backstage/core-components": "^0.7.0",
     "@backstage/core-plugin-api": "^0.1.10",
+    "@backstage/errors": "^0.1.2",
     "@backstage/integration": "^0.6.8",
     "@backstage/integration-react": "^0.1.12",
     "@backstage/plugin-catalog-react": "^0.6.0",
diff --git a/plugins/catalog-import/src/components/StepInitAnalyzeUrl/StepInitAnalyzeUrl.tsx b/plugins/catalog-import/src/components/StepInitAnalyzeUrl/StepInitAnalyzeUrl.tsx
index 75910db5a2..7784aa7284 100644
--- a/plugins/catalog-import/src/components/StepInitAnalyzeUrl/StepInitAnalyzeUrl.tsx
+++ b/plugins/catalog-import/src/components/StepInitAnalyzeUrl/StepInitAnalyzeUrl.tsx
@@ -113,8 +113,8 @@ export const StepInitAnalyzeUrl = ({
             break;
           }
         }
-      } catch (e) {
-        setError(e.data?.error?.message ?? e.message);
+      } catch (e: any) {
+        setError(e?.data?.error?.message ?? e.message);
         setSubmitted(false);
       }
     },
diff --git a/plugins/catalog-import/src/components/StepPrepareCreatePullRequest/StepPrepareCreatePullRequest.tsx b/plugins/catalog-import/src/components/StepPrepareCreatePullRequest/StepPrepareCreatePullRequest.tsx
index 6cabc52ddb..f441554119 100644
--- a/plugins/catalog-import/src/components/StepPrepareCreatePullRequest/StepPrepareCreatePullRequest.tsx
+++ b/plugins/catalog-import/src/components/StepPrepareCreatePullRequest/StepPrepareCreatePullRequest.tsx
@@ -16,6 +16,7 @@
 
 import { Entity } from '@backstage/catalog-model';
 import { errorApiRef, useApi } from '@backstage/core-plugin-api';
+import { assertError } from '@backstage/errors';
 import {
   catalogApiRef,
   formatEntityRefTitle,
@@ -174,6 +175,7 @@ export const StepPrepareCreatePullRequest = ({
           { notRepeatable: true },
         );
       } catch (e) {
+        assertError(e);
         setError(e.message);
         setSubmitted(false);
       }
diff --git a/plugins/catalog-import/src/components/StepReviewLocation/StepReviewLocation.tsx b/plugins/catalog-import/src/components/StepReviewLocation/StepReviewLocation.tsx
index 99dc972678..5c4f9b9594 100644
--- a/plugins/catalog-import/src/components/StepReviewLocation/StepReviewLocation.tsx
+++ b/plugins/catalog-import/src/components/StepReviewLocation/StepReviewLocation.tsx
@@ -25,6 +25,7 @@ import { PrepareResult, ReviewResult } from '../useImportState';
 import { configApiRef, useApi } from '@backstage/core-plugin-api';
 import { Link } from '@backstage/core-components';
 import { stringifyEntityRef } from '@backstage/catalog-model';
+import { assertError } from '@backstage/errors';
 
 type Props = {
   prepareResult: PrepareResult;
@@ -88,6 +89,7 @@ export const StepReviewLocation = ({
         locations,
       });
     } catch (e) {
+      assertError(e);
       // TODO: this error should be handled differently. We add it as 'optional' and
       //       it is not uncommon that a PR has not been merged yet.
       if (
diff --git a/plugins/catalog-react/package.json b/plugins/catalog-react/package.json
index af56fb2d44..2e9fa8fdd6 100644
--- a/plugins/catalog-react/package.json
+++ b/plugins/catalog-react/package.json
@@ -34,6 +34,7 @@
     "@backstage/core-app-api": "^0.1.17",
     "@backstage/core-components": "^0.7.0",
     "@backstage/core-plugin-api": "^0.1.10",
+    "@backstage/errors": "^0.1.2",
     "@backstage/integration": "^0.6.8",
     "@backstage/version-bridge": "^0.1.0",
     "@material-ui/core": "^4.12.2",
diff --git a/plugins/catalog-react/src/components/UnregisterEntityDialog/UnregisterEntityDialog.tsx b/plugins/catalog-react/src/components/UnregisterEntityDialog/UnregisterEntityDialog.tsx
index 4dce00e7b7..5c267916ea 100644
--- a/plugins/catalog-react/src/components/UnregisterEntityDialog/UnregisterEntityDialog.tsx
+++ b/plugins/catalog-react/src/components/UnregisterEntityDialog/UnregisterEntityDialog.tsx
@@ -33,6 +33,7 @@ import { useUnregisterEntityDialogState } from './useUnregisterEntityDialogState
 
 import { alertApiRef, configApiRef, useApi } from '@backstage/core-plugin-api';
 import { Progress, ResponseErrorPanel } from '@backstage/core-components';
+import { assertError } from '@backstage/errors';
 
 const useStyles = makeStyles({
   advancedButton: {
@@ -70,6 +71,7 @@ const Contents = ({
           await state.unregisterLocation();
           onConfirm();
         } catch (err) {
+          assertError(err);
           alertApi.post({ message: err.message });
         } finally {
           setBusy(false);
@@ -87,6 +89,7 @@ const Contents = ({
           await state.deleteEntity();
           onConfirm();
         } catch (err) {
+          assertError(err);
           alertApi.post({ message: err.message });
         } finally {
           setBusy(false);
diff --git a/plugins/catalog/src/components/EntityOrphanWarning/DeleteEntityDialog.tsx b/plugins/catalog/src/components/EntityOrphanWarning/DeleteEntityDialog.tsx
index cb5ea98031..20aa673ea3 100644
--- a/plugins/catalog/src/components/EntityOrphanWarning/DeleteEntityDialog.tsx
+++ b/plugins/catalog/src/components/EntityOrphanWarning/DeleteEntityDialog.tsx
@@ -19,6 +19,7 @@ import { catalogApiRef } from '@backstage/plugin-catalog-react';
 import { Button, Dialog, DialogActions, DialogTitle } from '@material-ui/core';
 import React, { useState } from 'react';
 import { alertApiRef, useApi } from '@backstage/core-plugin-api';
+import { assertError } from '@backstage/errors';
 
 type Props = {
   open: boolean;
@@ -44,6 +45,7 @@ export const DeleteEntityDialog = ({
       await catalogApi.removeEntityByUid(uid!);
       onConfirm();
     } catch (err) {
+      assertError(err);
       alertApi.post({ message: err.message });
     } finally {
       setBusy(false);
diff --git a/plugins/code-coverage-backend/src/service/CoverageUtils.test.ts b/plugins/code-coverage-backend/src/service/CoverageUtils.test.ts
index b666e042de..97a99c10b2 100644
--- a/plugins/code-coverage-backend/src/service/CoverageUtils.test.ts
+++ b/plugins/code-coverage-backend/src/service/CoverageUtils.test.ts
@@ -208,7 +208,7 @@ describe('CodeCoverageUtils', () => {
         };
         // @ts-ignore
         utils.validateRequestBody(mockRequest as Request);
-      } catch (error) {
+      } catch (error: any) {
         err = error;
       }
       expect(err?.message).toEqual('Content-Type missing');
@@ -226,7 +226,7 @@ describe('CodeCoverageUtils', () => {
 
         // @ts-ignore
         utils.validateRequestBody(mockRequest as Request);
-      } catch (error) {
+      } catch (error: any) {
         err = error;
       }
       expect(err?.message).toEqual('Illegal Content-Type');
diff --git a/plugins/kubernetes-backend/package.json b/plugins/kubernetes-backend/package.json
index 0e6848ca53..b2026faea6 100644
--- a/plugins/kubernetes-backend/package.json
+++ b/plugins/kubernetes-backend/package.json
@@ -35,6 +35,7 @@
     "@backstage/backend-common": "^0.9.4",
     "@backstage/catalog-model": "^0.9.3",
     "@backstage/config": "^0.1.10",
+    "@backstage/errors": "^0.1.2",
     "@backstage/plugin-kubernetes-common": "^0.1.4",
     "@google-cloud/container": "^2.2.0",
     "@kubernetes/client-node": "^0.15.0",
diff --git a/plugins/kubernetes-backend/src/cluster-locator/GkeClusterLocator.test.ts b/plugins/kubernetes-backend/src/cluster-locator/GkeClusterLocator.test.ts
index 7b2dfbf8de..545f839907 100644
--- a/plugins/kubernetes-backend/src/cluster-locator/GkeClusterLocator.test.ts
+++ b/plugins/kubernetes-backend/src/cluster-locator/GkeClusterLocator.test.ts
@@ -213,7 +213,7 @@ describe('GkeClusterLocator', () => {
       } as any);
 
       await expect(sut.getClusters()).rejects.toThrow(
-        'There was an error retrieving clusters from GKE for projectId=some-project region=some-region : [some error]',
+        'There was an error retrieving clusters from GKE for projectId=some-project region=some-region; caused by Error: some error',
       );
 
       expect(mockedListClusters).toBeCalledTimes(1);
diff --git a/plugins/kubernetes-backend/src/cluster-locator/GkeClusterLocator.ts b/plugins/kubernetes-backend/src/cluster-locator/GkeClusterLocator.ts
index 3cc6c216ae..7492ca88d3 100644
--- a/plugins/kubernetes-backend/src/cluster-locator/GkeClusterLocator.ts
+++ b/plugins/kubernetes-backend/src/cluster-locator/GkeClusterLocator.ts
@@ -15,6 +15,7 @@
  */
 
 import { Config } from '@backstage/config';
+import { ForwardedError } from '@backstage/errors';
 import * as container from '@google-cloud/container';
 import { GKEClusterDetails, KubernetesClustersSupplier } from '../types/types';
 
@@ -65,8 +66,9 @@ export class GkeClusterLocator implements KubernetesClustersSupplier {
         skipTLSVerify,
       }));
     } catch (e) {
-      throw new Error(
-        `There was an error retrieving clusters from GKE for projectId=${projectId} region=${region} : [${e.message}]`,
+      throw new ForwardedError(
+        `There was an error retrieving clusters from GKE for projectId=${projectId} region=${region}`,
+        e,
       );
     }
   }
diff --git a/plugins/scaffolder-backend/src/scaffolder/actions/builtin/github/githubWebhook.ts b/plugins/scaffolder-backend/src/scaffolder/actions/builtin/github/githubWebhook.ts
index 6d8324768e..0761f65f09 100644
--- a/plugins/scaffolder-backend/src/scaffolder/actions/builtin/github/githubWebhook.ts
+++ b/plugins/scaffolder-backend/src/scaffolder/actions/builtin/github/githubWebhook.ts
@@ -17,6 +17,7 @@ import { ScmIntegrationRegistry } from '@backstage/integration';
 import { createTemplateAction } from '../../createTemplateAction';
 import { OctokitProvider } from './OctokitProvider';
 import { emitterEventNames } from '@octokit/webhooks';
+import { assertError } from '@backstage/errors';
 
 type ContentType = 'form' | 'json';
 
@@ -130,6 +131,7 @@ export function createGithubWebhookAction(options: {
         });
         ctx.logger.info(`Webhook '${webhookUrl}' created successfully`);
       } catch (e) {
+        assertError(e);
         ctx.logger.warn(
           `Failed: create webhook '${webhookUrl}' on repo: '${repo}', ${e.message}`,
         );
diff --git a/plugins/scaffolder-backend/src/scaffolder/actions/builtin/helpers.ts b/plugins/scaffolder-backend/src/scaffolder/actions/builtin/helpers.ts
index 3907bc1d4e..eff65e329f 100644
--- a/plugins/scaffolder-backend/src/scaffolder/actions/builtin/helpers.ts
+++ b/plugins/scaffolder-backend/src/scaffolder/actions/builtin/helpers.ts
@@ -19,6 +19,7 @@ import { PassThrough, Writable } from 'stream';
 import { Logger } from 'winston';
 import { Git } from '@backstage/backend-common';
 import { Octokit } from '@octokit/rest';
+import { assertError } from '@backstage/errors';
 
 export type RunCommandOptions = {
   command: string;
@@ -152,6 +153,7 @@ export const enableBranchProtectionOnDefaultRepoBranch = async ({
         },
       });
     } catch (e) {
+      assertError(e);
       if (
         e.message.includes(
           'Upgrade to GitHub Pro or make this repository public to enable this feature',
diff --git a/plugins/scaffolder-backend/src/scaffolder/actions/builtin/publish/github.ts b/plugins/scaffolder-backend/src/scaffolder/actions/builtin/publish/github.ts
index b32f9b5b3f..ad6a4a7857 100644
--- a/plugins/scaffolder-backend/src/scaffolder/actions/builtin/publish/github.ts
+++ b/plugins/scaffolder-backend/src/scaffolder/actions/builtin/publish/github.ts
@@ -22,6 +22,7 @@ import { getRepoSourceDirectory } from './util';
 import { createTemplateAction } from '../../createTemplateAction';
 import { Config } from '@backstage/config';
 import { OctokitProvider } from '../github/OctokitProvider';
+import { assertError } from '@backstage/errors';
 
 type Permission = 'pull' | 'push' | 'admin' | 'maintain' | 'triage';
 type Collaborator = { access: Permission; username: string };
@@ -198,6 +199,7 @@ export function createPublishGithubAction(options: {
               permission,
             });
           } catch (e) {
+            assertError(e);
             ctx.logger.warn(
               `Skipping ${permission} access for ${team_slug}, ${e.message}`,
             );
@@ -213,6 +215,7 @@ export function createPublishGithubAction(options: {
             names: topics.map(t => t.toLowerCase()),
           });
         } catch (e) {
+          assertError(e);
           ctx.logger.warn(`Skipping topics ${topics.join(' ')}, ${e.message}`);
         }
       }
@@ -250,6 +253,7 @@ export function createPublishGithubAction(options: {
           requireCodeOwnerReviews,
         });
       } catch (e) {
+        assertError(e);
         ctx.logger.warn(
           `Skipping: default branch protection on '${newRepo.name}', ${e.message}`,
         );
diff --git a/plugins/scaffolder-backend/src/scaffolder/tasks/StorageTaskBroker.ts b/plugins/scaffolder-backend/src/scaffolder/tasks/StorageTaskBroker.ts
index 867e5bb127..4cd1066fc9 100644
--- a/plugins/scaffolder-backend/src/scaffolder/tasks/StorageTaskBroker.ts
+++ b/plugins/scaffolder-backend/src/scaffolder/tasks/StorageTaskBroker.ts
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 import { JsonObject } from '@backstage/config';
+import { assertError } from '@backstage/errors';
 import { Logger } from 'winston';
 import {
   CompletedTaskState,
@@ -185,6 +186,7 @@ export class StorageTaskBroker implements TaskBroker {
           try {
             callback(undefined, result);
           } catch (error) {
+            assertError(error);
             callback(error, { events: [] });
           }
         }
diff --git a/plugins/scaffolder-backend/src/scaffolder/tasks/TaskWorker.ts b/plugins/scaffolder-backend/src/scaffolder/tasks/TaskWorker.ts
index 7122c2fc3e..6a5a1f7843 100644
--- a/plugins/scaffolder-backend/src/scaffolder/tasks/TaskWorker.ts
+++ b/plugins/scaffolder-backend/src/scaffolder/tasks/TaskWorker.ts
@@ -13,8 +13,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 import { Task, TaskBroker, WorkflowRunner } from './types';
 import { LegacyWorkflowRunner } from './LegacyWorkflowRunner';
+import { assertError } from '@backstage/errors';
 
 type Options = {
   taskBroker: TaskBroker;
@@ -44,6 +46,7 @@ export class TaskWorker {
 
       await task.complete('completed', { output });
     } catch (error) {
+      assertError(error);
       await task.complete('failed', {
         error: { name: error.name, message: error.message },
       });
diff --git a/plugins/scaffolder-backend/src/service/helpers.ts b/plugins/scaffolder-backend/src/service/helpers.ts
index 7125e9df93..6741ab3379 100644
--- a/plugins/scaffolder-backend/src/service/helpers.ts
+++ b/plugins/scaffolder-backend/src/service/helpers.ts
@@ -21,6 +21,7 @@ import {
   SOURCE_LOCATION_ANNOTATION,
 } from '@backstage/catalog-model';
 import { Config } from '@backstage/config';
+import { assertError } from '@backstage/errors';
 import fs from 'fs-extra';
 import os from 'os';
 import { Logger } from 'winston';
@@ -39,6 +40,7 @@ export async function getWorkingDirectory(
     await fs.access(workingDirectory, fs.constants.F_OK | fs.constants.W_OK);
     logger.info(`using working directory: ${workingDirectory}`);
   } catch (err) {
+    assertError(err);
     logger.error(
       `working directory ${workingDirectory} ${
         err.code === 'ENOENT' ? 'does not exist' : 'is not writable'
diff --git a/plugins/techdocs-backend/src/DocsBuilder/builder.ts b/plugins/techdocs-backend/src/DocsBuilder/builder.ts
index 5327062233..821b3478a0 100644
--- a/plugins/techdocs-backend/src/DocsBuilder/builder.ts
+++ b/plugins/techdocs-backend/src/DocsBuilder/builder.ts
@@ -19,7 +19,7 @@ import {
   stringifyEntityRef,
 } from '@backstage/catalog-model';
 import { Config } from '@backstage/config';
-import { NotModifiedError } from '@backstage/errors';
+import { assertError, isError } from '@backstage/errors';
 import { ScmIntegrationRegistry } from '@backstage/integration';
 import {
   GeneratorBase,
@@ -131,7 +131,7 @@ export class DocsBuilder {
       preparedDir = preparerResponse.preparedDir;
       newEtag = preparerResponse.etag;
     } catch (err) {
-      if (err instanceof NotModifiedError) {
+      if (isError(err) && err.name === 'NotModifiedError') {
         // No need to prepare anymore since cache is valid.
         // Set last check happened to now
         new BuildMetadataStorage(this.entity.metadata.uid).setLastUpdated();
@@ -142,7 +142,7 @@ export class DocsBuilder {
         );
         return false;
       }
-      throw new Error(err.message);
+      throw err;
     }
 
     this.logger.info(
@@ -195,6 +195,7 @@ export class DocsBuilder {
         // Not a blocker hence no need to await this.
         fs.remove(preparedDir);
       } catch (error) {
+        assertError(error);
         this.logger.debug(`Error removing prepared directory ${error.message}`);
       }
     }
@@ -221,6 +222,7 @@ export class DocsBuilder {
         `Removing generated directory ${outputDir} since the site has been published`,
       );
     } catch (error) {
+      assertError(error);
       this.logger.debug(`Error removing generated directory ${error.message}`);
     }
 
diff --git a/plugins/techdocs-backend/src/service/DocsSynchronizer.ts b/plugins/techdocs-backend/src/service/DocsSynchronizer.ts
index 463b895564..6f977dcb47 100644
--- a/plugins/techdocs-backend/src/service/DocsSynchronizer.ts
+++ b/plugins/techdocs-backend/src/service/DocsSynchronizer.ts
@@ -16,7 +16,7 @@
 
 import { Entity } from '@backstage/catalog-model';
 import { Config } from '@backstage/config';
-import { NotFoundError } from '@backstage/errors';
+import { assertError, NotFoundError } from '@backstage/errors';
 import { ScmIntegrationRegistry } from '@backstage/integration';
 import {
   GeneratorBuilder,
@@ -113,6 +113,7 @@ export class DocsSynchronizer {
         return;
       }
     } catch (e) {
+      assertError(e);
       const msg = `Failed to build the docs page: ${e.message}`;
       taskLogger.error(msg);
       this.logger.error(msg, e);