Since yesterday (October 2nd, 2014), there seem to be random errors when trying to access apps that use OAuth 2.
There are two problems:
We can\'t a
I caused the same problem at OpenID Connect authentication, so I had been made a query to Google Cloud Platform support.
Google updated to be not able to short name scope on Marketplace (without an announcement). Now Google are considering to re-use short name scopes. So We have to use long URL scope until Google corresponding to complete.
We are getting the same issue on our application. I have tested with using long names for scopes, but it did not help.
Also, it appears that the error only occurs from a Google Apps account. Regular Google account works fine.
The error does not occur for the users who have already given permission to the application.