Open Radar

 
Typically Game Center's login window will stop showing if the user cancels it too many times (I believe it's 3 now?). Once the user gets into this state NO app will no longer request their login credentials for Game Center. 

This is a problem on testing iOS 7 apps in the Game Center sandbox unfortunately. Once the device is in this state there is no way to authenticate with Game Center's sandbox servers anymore. On iOS 6 you could log into the Sandbox environment via the Game Center app, but you can't do this on iOS 7. 

The only way I found to fix this problem is to wipe the device completely or use the Reset Settings option under Settings->General->Reset which keeps your content but forgets a lot of built in settings. 

This becomes a major problem when not only developing an game but also when/if you have users testing the game. Having to tell a tester, some of which are end users, to reset their device if they accidentally hit cancel a few times is not a good things to do.

STEPS: 

1. Install/Run a Game Center Sandbox/Debug enabled app.
2. Hit Cancel on the Game Center Login Prompt.
3. Repeat Steps 1 & 2 until No More Login prompt is given on app launch
4. Now try to log into the Game Center Sandbox

Expected:
There would be a way for a user to log back into Game Center Sandbox. 

Actual Results:
On iOS 6 you would visit the GameCenter.app to log into Game Center Sandbox. On iOS 7 due to changes to how Game Center works this is no longer an option. 

The user is stuck unable to log into Game Center's Sandbox without forcing a reset of the device. 

Regression:

There was a way to do this on iOS 6, no way to do this on iOS 7