Firebase Android: An internal error has occurred. [ OPERATION_NOT_ALLOWED ]

Question

Signing in via Google in my application gives this error:

An internal error has occurred. [ OPERATION_NOT_ALLOWED ]

I have enabl

Answer 1

I had the same problem. I got the solution in the forum post [Google Auth] com.google.firebase.FirebaseException: An internal error has occurred.

This happened to me when I did not have the authentication method enabled in the console Firebase. When I enabled Google authentication, I got the same exception, just without [OPERATION_NOT_ALLOWED].