Why Does the Google Drive Copy Node Randomly Return a 'Forbidden - perhaps check your credentials' Error?

Below is an explanation and some troubleshooting steps based on known issues with Google node operations:

What’s Happening

The error message:

  “Forbidden - perhaps check your credentials”

typically indicates that Google is rejecting the authentication request. While many have seen this in Gmail-related operations (especially with Service Account credentials without impersonation enabled), similar issues can also occur in Google Drive nodes when the credentials aren’t fully set up for the intended operations.

Possible Causes and Resolutions

1. OAuth Credentials Mismatch

   • If you’re using OAuth credentials, ensure that the URLs configured in Google’s OAuth settings exactly match those used by your n8n instance.
   • For self-hosted setups, verify that the [N8N_EDITOR_BASE_URL] and [WEBHOOK_URL] environment variables are set to fully qualified domains.
   • Even on n8n cloud, double-check that the OAuth consent screen and API configuration meet Google’s security requirements.

2. Service Account and Impersonation

   • If you’re using a Google Service Account, this error can occur if the credential isn’t configured to impersonate a user.
   • Enable the Impersonate a User option for your Google Service Account credentials and make sure to provide the correct email address of a user who has authorization to perform the requested operations.

3. Intermittent Authorization Issues

   • Since the workflow runs fine on subsequent executions, it might be a temporary hiccup. If the settings above are correct and verified, consider if there are any rate limits or sporadic issues on the Google API side.

Summary

The error is most likely due to one of the following:

• A configuration mismatch in your OAuth setup (wrong URLs, unverified app settings, etc.)
• Missing or misconfigured impersonation when using a Google Service Account

Double-check your credentials setup in n8n against Google’s API requirements. Adjust your OAuth or Service Account settings accordingly to resolve the “Forbidden - perhaps check your credentials” error.

If issues persist, reviewing the detailed steps in the documentation for setting up Google credentials in n8n may offer further insights.