I just unlocked my phone to realize that my Game Center account has been removed. I tried to sign in with my Game Center account I already had, but it created a new one. It says Sandbox at the bottom-left corner. I had over 500 games, and a ton of achievements, and I am extremely angry because I lost it all. Any solutions?
I just unlocked my phone too, today. My GC is fine. No idea what you could do.. Maybe a hard reset? Or sign out of Apple ID.. Try both methods.
That happened to me when I installed a provision profile. I freaked out to but the problem went away by itself after awhile.
If you're beta testing games, they sometimes use the sandbox GC, but you can usually log out and then log back in to your regular GC account.