One of our games on the PlayStore was accidentally enrolled into Google Play App Signing. No idea how it happened, but we probably just accidentally uploaded our KEY and even we didn't encrypt it, Google accepted it.
Now we have an App Signing Certificate and an Upload Certificate which we don't know how to use. It seems that this messes as well with the Google Play Service and the Leaderboard with the consequence that the player can't log in. It seems we are managin two version of the same app. Two different SHA-1 Certificates. So once we upoad the game with the original KEY, it then gets automatically changed by Google Play. The strangest thing is that we still can sign the app with the old KEY generated within Eclipse when we first exported the game. Something that according to Google guidelines should not be possible.
We hope/guess that there is a simple solution to the problem, but we need to make it work with Eclipse which is the only app we can run our app in, since we used Buildbox to create the game.
If you are an expert in Eclipse and Google Play Service please help us resolve this issue as soon as possible and show us how we can keep working with the new Certificates for future updates.