python 2.7 - Switched from Federated Login back to Google Accounts API

in preparation depreciation of federated logins, moved users on own login system - no problems there.

however hoping continue use users api continue login admin access parts of application admin specified app.yaml

in dashboard have changed authentication type google accounts api when browse login url below server error.

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

any ideas?

Fun enginering