title: SwiftUI Beta 3 Black Screen
body: <p>I just converted to beta 3 and my previously working SwiftUI code is now rendering a plain black screen.  Was there a change in beta 3 that is causing this. Is there a solution to fix it?  </p>
  
  <p>Scene delegate code: </p>
  
  <pre><code>    func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
          // Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
          // If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
          // This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).
  
          // Use a UIHostingController as window root view controller
  
  
      let window = UIWindow(frame: UIScreen.main.bounds)
  
  
       window.rootViewController = UIHostingController(rootView: ContentView())
       self.window = window
       window.makeKeyAndVisible()
  
      }
  </code></pre>