title: WPF Application fails on startup with TypeInitializationException
body: <p>I have a simple WPF application which I am trying to start.  I am following the Microsoft Patterns and Practices "Composite Application Guidance for WPF".  I've followed their instructions however my WPF application fails immediately with a "TypeInitializationException".</p>
  
  <p>The InnerException property reveals that "The type initializer for 'System.Windows.Navigation.BaseUriHelper' threw an exception."</p>
  
  <p>Here is my app.xaml:</p>
  
  <pre><code>&lt;Application x:Class="MyNamespace.App"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"&gt;
      &lt;Application.Resources&gt;         
      &lt;/Application.Resources&gt;
  &lt;/Application&gt;
  </code></pre>
  
  <p>And here is my app.xaml.cs (exception thrown at "public App()"):</p>
  
  <pre><code>public partial class App : Application
  {
      public App()
      {
          Bootstrapper bootStrapper = new Bootstrapper();
          bootStrapper.Run();
      }
  }
  </code></pre>
  
  <p>I have set the "App" class as the startup object in the project.</p>
  
  <p>What is going astray?</p>