Error "Your migration failed checking source credentials. Cannot connect to Drive API: Error:"unauthorized_client", Description:"Client is unauthorized to retrieve access tokens using this method.", Uri:"""
This error occurs in a Google Drive migration when Enable API Access has not been enabled in the Google Admin Portal.
To enable API Access, follow these steps.
Note: Google has limited this setting to G Suite Super Administrators only.
- Log in to the Google Admin Portal
- Click on Security
- Click on API Permissions.
- Make sure that Drive is marked Enable.
- This step is required for both the Source and Destination Admin Portals when migrating from Google Drive to Google Drive.
- For best results, we suggest following the steps in this article to make sure that all access needed is granted to the migration account: Enable access to G Suite (IMAP) using OAuth 2.0