I made the integration once into the game I am working on and never had the issue before.
Recently I am having a new log from Xcode and not sure what is going on.
Then from an empty scene, I created a single button to call the login process to call the following :
No problem at all on first click, the GameCenter Login UI show up.
If you login, you can access to the achievement UI, report score, etc…
Now if during the login UI you press the Cancel button to close the GameCenter.
if you press again on the same button to call the login as previously done, Xcode will return the following message :
Failed to authenticate local user The requested operation has been canceled or disabled by the user.
It seems as long as the user Canceled at least once the login process, it is not possible to call the GameCenter login anymore.
The app has to be crashed, and restarted to access to the first time login.