Could not connect to the Game Center Server - ios

Question

I am trying to integrate Game Centre to my Sprite Kit game. I am referring to this link:
http://www.appcoda.com/ios-game-kit-framework/
I have created a record on my iTunes Connect account for the game I am building. I try connecting to the Game Centre in the Simulator by trying to login through the Game Centre App itself and it gives me this error:
Could not Connect to the Game Center Server
And if I try to login through settings > Game Center, I get an error saying:
Unable to connect to server,
The network connection was lost
When I open my game, I have code written which checks if there is an authenticated user or not, and if not, it shows up the login to game centre scene. It showed this a couple of times but I canceled it because I kept getting the first error. Now that screen doesn't even show up.
What am I doing wrong?
PS: I have Game Centre enabled in my game in the capabilities menu.
EDIT:
This is in my viewController.m:
-(void)authenticateLocalPlayer {
GKLocalPlayer *localPlayer = [GKLocalPlayer localPlayer];
localPlayer.authenticateHandler = ^(UIViewController *viewController, NSError *error){
if (viewController != nil) {
[self presentViewController:viewController animated:YES completion:nil];
}
else{
if ([GKLocalPlayer localPlayer].authenticated) {
gameCenterEnabled = YES;
// Get the default leaderboard identifier.
[[GKLocalPlayer localPlayer] loadDefaultLeaderboardIdentifierWithCompletionHandler:^(NSString *leaderboardIdentifier, NSError *error) {
if (error != nil) {
NSLog(#"%#", [error localizedDescription]);
}
else{
leaderboardIdentifier = leaderboardIdentifier;
}
}];
}
else{
gameCenterEnabled = NO;
}
}
};
}
I call it in the viewDidLoad of my viewController.m

Answer 1

Issue might be with your device and not your code. Try these steps:
Press and hold the Sleep/Wake button and the Home button together for at least ten seconds, until the Apple logo appears.
If that doesn't help, tap Settings -> General -> Reset -> Reset Network Settings.
You will have to re-enter your WiFi password.
Also confirm your device Apple ID matches your developer ID.