Hi @markhanson, I am sorry to hear you’re having this problem. I’ve tested out my trusty old Google OAuth2 credentials from last year, but they are still working as expected and didn’t expire.
So I wonder if the problem here could be slightly different. Are you using the latest version of n8n? Since version 0.156.0 you should see the error response body in the UI when opening the node that failed to execute. Could you check the node for a more detailed error message?