Switched from Federated Login back to Google Accounts API - nothing but errors

In preparation for depreciating Federated Logins, I migrated my users to my login system - no problem.

However, I was hoping to continue using the user APIs to continue logging in as an administrator so that I can only access the parts of the application that are administrators as specified in app.yaml

In the control panel, I changed the authentication type to Google Accounts API, but when I view the login url below, I get a server error.

https://triton.ironhelmet.com/_ah/login?continue=https://triton.ironhelmet.com

      

        
        
        
      

    

Any ideas?