n8n-io/n8n · error · InternalServerError

Failed to load headers file

Error message

Failed to load headers file

What it means

The node-translation-headers endpoint first checks the headers file exists (access .js); if present but require() throws, the controller wraps the failure as 500 InternalServerError 'Failed to load headers file' with the original error attached.

Source

Thrown at packages/cli/src/controllers/translation.controller.ts:60

			return require(translationPath);
		} catch (error) {
			return null;
		}
	}

	@Get('/node-translation-headers')
	async getNodeTranslationHeaders() {
		try {
			await access(`${NODE_HEADERS_PATH}.js`);
		} catch {
			return; // no headers available
		}

		try {
			// eslint-disable-next-line @typescript-eslint/no-unsafe-return
			return require(NODE_HEADERS_PATH);
		} catch (error) {
			throw new InternalServerError('Failed to load headers file', error);
		}
	}
}

View on GitHub (pinned to 5ac6606e81)

Solutions

1. Regenerate the node-translation headers bundle (rebuild) so the file is valid.
2. Delete the stale headers file and rebuild so it is produced cleanly.
3. Inspect the attached original error in server logs to find the require() failure (syntax error, missing export).

// No pure pre-check; ensure a clean build produced the headers file. Caller can fall back to no headers on 500.
function shouldAttemptHeaders() { return true; } // guarded by try/catch below

try {
  await api.get('/node-translation-headers');
} catch (e) {
  if (e.status === 500 && /Failed to load headers file/.test(e.message)) {
    // rebuild to regenerate the headers bundle; fall back to no custom headers meanwhile
  } else { throw e; }
}

When it happens

Trigger: GET /node-translation-headers where NODE_HEADERS_PATH.js exists (access succeeds) but require(NODE_HEADERS_PATH) throws — corrupt, truncated, or syntactically invalid generated headers bundle.

Common situations: A partial/interrupted build left a malformed headers file; the headers generation step wrote an empty or syntactically broken module; version skew between the headers bundle and the runtime.

Related errors

• Third-party licenses file not found
• Invalid Credential type: "${credentialType}"
• Agent "${this.name}" requires a model
• Agent "${this.name}" requires instructions
• NODE_NOT_FOUND

AI-assisted analysis of n8n-io/n8n@5ac6606e81 (2026-08-12). Data as JSON: /api/errors/947d58719141d4d5. Report an issue: GitHub.