Gmail IMAP OAuth2 returns error code 400

Question

When trying to connect to the Google IMAP service using the XOAUTH2 mechanism (https://developers.google.com/google-apps/gmail/xoauth2_protocol), I sometimes receive the following error response:

{"status":"400","schemes":"Bearer","scope":"https://mail.google.com/"}

I was wondering if anyone knew what exactly that status 400 was ...

Answer 1

Error message seems to happen when you use an expired access token.