I'm trying to use this excellent plugin on all my sites, backing up onto one Google Drive - one website per folder. The first site I authorise works great - no problems. But when I try to authorise the second site, I get that error which is fixed by revoking access using the Google accounts page. No problem.. I just revoke access, and then authorise the plugin again in the plugin settings. Now the second site works! But of course the other site won't back up to Google Drive (presumably because access has been revoked!) and the log shows the error:
The server returned code 400 Bad Request while trying to obtain an access token. (bad_response)
Obviously I can't grant access to more than one site with the same Client ID. So, do you know a way to back up multiple sites using one Drive? Do I need multiple client IDs?