I noticed today, after a few failed attempts, that the Google API instructions in the docs... /17.0/applications/productivity/calendar/google.html

seems to have a small error. The URI for authentication seems wrong. The docs reference the URI as /google_account/authentication 

In my case at least, I added a second URI to the google OAuth list:

Under the Google API - "Authorized redirect URIs" I added "google_gmail/confirm" 

after that, retrying the calendar and email Google OAuth steps worked fine.

Am I missing something?

Do we actually need both "authentication" and "confirm"?

David