title: StoryBoard.InstantiateViewController giving "Unknown class testController in Interface Builder file"
body: <p>I am working on a Xamarin IOS/monotouch project. 
  I have been stuck with this error since some time. These are the lines of code</p>
  
  <pre><code>var prfc = this.Storyboard.InstantiateViewController ("testController") as testController;
              if (prfc != null) {
                  this.PresentViewController(prfc,false,null);}
  </code></pre>
  
  <p>I tried renaming viewcontroller, cleaning and building solution, deleting viewcontroller and adding a new one with another name
  I have ensured that all spellings are correct, i have same Viewcontroller name, StoryBoardID, and Restoration ID. This is how I have registered my viewcontroller in Designer partial class</p>
  
  <pre><code>[Register ("testController")]
  partial class testController
  </code></pre>
  
  <p>Here is my appdelegate.cs code `[Register ("AppDelegate")] public partial class AppDelegate : UIApplicationDelegate { // class-level declarations UIWindow window; public static UIStoryboard Storyboard = UIStoryboard.FromName ("MainStoryboard", null); public static UIViewController initialViewController; public override UIWindow Window { get; set; }</p>
  
  <pre><code>`[Register ("AppDelegate")] public partial class AppDelegate : UIApplicationDelegate { // class-level declarations UIWindow window; public static UIStoryboard Storyboard = UIStoryboard.FromName ("MainStoryboard", null); public static UIViewController initialViewController; public override UIWindow Window { get; set; }
  // This method is invoked when the application is about to move from active to inactive state.
  // OpenGL applications should use this method to pause.
  public override void OnResignActivation (UIApplication application)
  {
  }
  
  // This method should be used to release shared resources and it should store the application state.
  // If your application supports background exection this method is called instead of WillTerminate
  // when the user quits.
  public override void DidEnterBackground (UIApplication application)
  {
  }
  
  // This method is called as part of the transiton from background to active state.
  public override void WillEnterForeground (UIApplication application)
  {
  }
  
  // This method is called when the application is about to terminate. Save data, if needed.
  public override void WillTerminate (UIApplication application)
  {
  }
  public override void FinishedLaunching (UIApplication application)
  {
      window = new UIWindow (UIScreen.MainScreen.Bounds);
  
      initialViewController = Storyboard.InstantiateInitialViewController () as UIViewController;
  
      window.RootViewController = initialViewController;
      window.MakeKeyAndVisible ();
      return ;
  }
  </code></pre>
  
  <p>}`</p>
  
  <p>I have tried out every possibility but can't fix this. This error is occuring for every new viewcontroller that I add to Storyboard. I am getting a null when I call InstantiateViewController. I have tried cleaning and rebuilding. It works on simulator, but not on device </p>