I have an Android game, written in Java. It uses Google Play Games Services for turn-based multiplayer and works already just fine.
However, for the past days I've been trying to integrate GameSparks into it (only the Leaderboards), to no avail. I just keep getting NOTAUTHENTICATED when I try to do a Google+ connect request.
I have checked like five times that ID's, secret keys, redirect URIs etc. are correct.
I even attempted certificate authentication, but the problem persists. (Btw. there does not seem to be an option to remove the certificate-file at all?)
I believe the problem is with access token / server auth code, since the problem happens even when I try do a "GooglePlusConnectRequest" in Test Harness. It is not null, however.
I simply use "requestServerAuthCode" with GoogleSignOptions to get the auth code.
Feel free to ask questions, and any ideas are greatly appreciated!