title: "Attempt by security transparent method" when re-opening a default application
body: <p>I created a new application with react native windows, and it works well the first (few) times I run it, however, when closing the application I always end up with the following warning:</p>
  
  <blockquote>
    <p>Attempt by security transparent method 'System.Reactive.Concurrency.CoreDispatcherScheduler..ctor(Windows.UI.Core.CoreDispatcher)' to access security-critical type 'Windows.UI.Core.CoreDispatcher' failed.</p>
  </blockquote>
  
  <p><img src="https://i.stack.imgur.com/X0Dc2.png" alt="Screenshot"></p>
  
  <p>I've tried this on more than one computer and all of them get the same error but I can't find a way to fix this, meaning I cant proceed with my Native project in fear that it will malfunction every day. 
  How do I fix this, to stop this from happening again, or is it a bug?</p>