How do I fix the error Incompatible pointer types sending 'NSString _strong' to parameter of type 'UIViewController*'? in Xcode
<p>Can anyone help me fix this error? Here is everything in the ViewController.m file. I've tried fixing it and searching online but nothing is helping. I already declared the GameScreenViewController, but now when I click the play button it goes to a black screen instead of a different screen I made. In the All Output it says 2012-06-05 12:54:52.652 parkour[4705:f803] Application tried to push a nil view controller on target </p>

<pre><code>-(IBAction)switchScreens:(id)sender{
    UINavigationController *navigationController = [[UINavigationController alloc]
                                                    **initWithRootViewController:GameScreenViewController];**
    [self presentViewController:navigationController animated:YES completion: nil];
}

@end
</code></pre>
