title: iOS App compiles and runs, just shows black screen
body: <p>Here's the rundown:</p>
  
  <ul>
  <li>The project build successfully</li>
  <li>When ran on XS Max simulator: the app shows the launch screen however, it shows only black after that with no run-time errors.</li>
  <li>When ran on any other simulator: the app shows the launch screen however, the app shows black but the console reads..</li>
  </ul>
  
  <blockquote>
    <p>libMobileGestalt MobileGestalt.c:890: MGIsDeviceOneOfType is not
    supported on this platform</p>
  </blockquote>
  
  <p>.</p>
  
  <p>I've updated the app from Swift 2 to 4.2. Most of the error fixes were just updating syntax.</p>
  
  <p>Any insight that would help solve this would be appreciated!</p>
  
  <pre><code>private func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: Any]?) -&gt; Bool {
      setConstants()
  
      window = UIWindow(frame: UIScreen.main.bounds)
      window!.rootViewController = RootViewController.sharedInstance
      window!.makeKeyAndVisible()
  
      preloadKeyboard()
  
      return true
  }
  </code></pre>
  
  <p>RootViewController's Shared Instance: </p>
  
  <pre><code>static let sharedInstance = RootViewController(nibName: "RootViewController", bundle: nil)
  </code></pre>
  
  <p>Why this is not a duplicate question:</p>
  
  <ul>
  <li>The MGc90 is not the main error I'm trying to resolve (the black screen is)</li>
  <li>Solutions from the link question do not fix the situation</li>
  <li>Sol#1 Xcode 9.4.1 yields the same error</li>
  <li>Sol#2 Removing private from didFinishLaunchingWithOptions only yields an error</li>
  <li>Sol#3 Gives good insight on what that error means and helps me understand why it's not showing an error on XS Max</li>
  <li>Sol#4 I don't have a breakpoint or an alert to continue</li>
  <li>Sol#5 I have no ambiguous layout warnings</li>
  <li>Sol#6 Deployment target is just fine</li>
  <li>Sol#7 I know the newer iPhone model doesn't yield the error but still shows black screen</li>
  <li>Sol#8 Fonts are loaded</li>
  <li>Sol#9 Another change simulator.</li>
  </ul>