I'm having a problem with GameCentre Leaderboard. When I call GameCentreShowLeaderBoard("my leaderbourd ID here"), I get an error message pop up saying "Unfortunately Google Play Games has stopped - Report / Ok". I have tried using the leaderboard ID (which is what I suspect I should be using), and I have tried using the leaderboard name.
With the ID, I get that error message, with the name is just hangs (whirls away like it's trying to load something).
Can anybody give me some pointers please? Do I need to publish the game for leaderboards to work? (Achievements are working fine in Test / Draft).