title: Game Center Authenticate Local Player
body: <p>I am trying to authenticate the local player using the following code:</p>
  
  <pre><code>GKLocalPlayer *localPlayer = [GKLocalPlayer localPlayer];
  if(!localPlayer.authenticated) {
      localPlayer.authenticateHandler = ^(UIViewController* controller, NSError *error) {
          if(controller != nil)
              [self presentModalViewController:controller animated:YES];
      };
  }
  </code></pre>
  
  <p>But the problem is that even though <code>[GKLocalPlayer localPlayer].authenticated</code> is false, the controller that is returned in the <code>authenticationHandler</code> block is always nil. Therefore gamer center always seems to be disabled.</p>