title: The program '[3708] BookLogistics.exe' has exited with code -1 (0xffffffff)
body: <p>I'm developing a Windows Phone 8.1 app. I suddenly faced an issue in which Windows Phone 8.1 emulator starts but app doesn't start and a file named 'App.g.i.cs' opens up and highlights the below line of code:<br>
  <code>global::System.Diagnostics.Debugger.Break();</code></p>
  
  <p><br>This code is contained inside the following code:</p>
  
  <pre><code>#if DEBUG &amp;&amp; !DISABLE_XAML_GENERATED_BREAK_ON_UNHANDLED_EXCEPTION
  UnhandledException += (sender, e) =&gt;
  {
      if (global::System.Diagnostics.Debugger.IsAttached) global::System.Diagnostics.Debugger.Break();
  };
  #endif
  </code></pre>
  
  <p>This happened after I installed Windows Phone 10 Emulator, I tried uninstalling WP 10 emulator but still facing the same problem.</p>
  
  <p>I tried to find the solution but didn't find any solution. I don't know whether I'm right or not but all I got to know is that application 'breaks' when Debugger is enabled.</p>
  
  <p><strong>Output:</strong>
  <a href="https://i.stack.imgur.com/S1uy6.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/S1uy6.png" alt="Output"></a></p>
  
  <p>Below is the screenshot of the problem:
  <a href="https://i.stack.imgur.com/57TZl.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/57TZl.png" alt="enter image description here"></a></p>
  
  <p><strong>Solution:</strong>
  After doing a bit of experiment I found that in the <code>MainPage.xaml</code> I've included a <code>&lt;TextBox&gt;</code> and after removing the following code from <code>&lt;TextBox&gt;</code> the app works perfectly:</p>
  
  <pre><code> &lt;TextBox.Header&gt;
       &lt;TextBlock Text="Email" FontFamily="Comic Sans MS"/&gt;
   &lt;/TextBox.Header&gt;
  </code></pre>