thank you very much! Working now.
On another note, I have a question:
Currently I have a game that asks the player to input a name for it to be used to update the scores. Im trying to remove this and link the name to the Apple game center nickname. Is there a way to link a GUID to an Apple nickname/gamecenter account so when the user re-installs the game gets the same GUID to update their own entry? (without having to use another DB to save nickname/GUID)
Saving to JSON persistent store doesn't work as Apple removes all files when uninstalling a game. Im also looking for players to connect with the same account from different devices.