n8n Workflow Fails with 'Unable to Sign without Access Token' Error

Below is a checklist of steps to troubleshoot this error:

1. Inspect Node Credentials
   The error “Unable to sign without access token” indicates that the node is trying to perform an authenticated operation without a valid access token. Open the “New File Is Added” node and verify that its credentials are correctly configured. This may mean:

   • Checking that you’ve provided a valid access token.
   • Re-authorizing or re-entering the credentials if the token has expired or been revoked.

2. Review Credential Persistence in Docker
   Since you are running n8n via Docker, make sure that any volume or directory where credentials are stored (typically in the persistent data folder) is correctly mounted. If the credentials file or persisted node data isn’t retained between container recreate or updates, the token might be missing at startup.

3. Examine Recent Changes in the External Service
   Even if the workflow wasn’t modified recently, the external service (whose API the node is using) might have updated its token requirements or invalidated tokens. Double-check the documentation of that external integration to see whether there’s a new authentication flow or updated token expiry.

4. Check Execution Logs for Additional Details
   Navigate to the Executions log in n8n. Detailed logs can often highlight if another underlying issue is causing the token error, such as an incorrect request format or network-related issues.

By following these steps, you should be able to identify whether the problem is due to:

• Missing or expired access tokens in your credentials,
• A misconfiguration stemming from the Docker persistence setup, or
• Changes in how the external service handles authentication.

Once you’ve confirmed the correct token is stored and properly referenced by the “New File Is Added” node, the error should resolve, allowing you to run and activate your workflow.