title: 'MS.Internal.Xaml.Parser.GenericTypeNameParser.TypeNameParserException' in System.Xaml.dll
body: <p>I am getting this exception now when I am attempting to run my project. I haven't changed any code.</p>
  <blockquote>
  <p>Exception thrown: 'MS.Internal.Xaml.Parser.GenericTypeNameParser.TypeNameParserException' in System.Xaml.dll</p>
  <p>Additional information: Prefix 'Custom' does not map to a namespace.</p>
  </blockquote>
  <p>&quot;Custom&quot; refers to the MAHapps metro toolkit in App.xaml:</p>
  <pre><code>&lt;Application xmlns=&quot;http://schemas.microsoft.com/winfx/2006/xaml/presentation&quot; 
           xmlns:x=&quot;http://schemas.microsoft.com/winfx/2006/xaml&quot; 
           xmlns:d=&quot;http://schemas.microsoft.com/expression/blend/2008&quot; 
           xmlns:d1p1=&quot;http://schemas.openxmlformats.org/markup-compatibility/2006&quot; 
           xmlns:Custom=&quot;http://metro.mahapps.com/winfx/xaml/controls&quot; 
           xmlns:Custom1=&quot;http://metro.mahapps.com/winfx/xaml/shared&quot; 
  </code></pre>
  <p>I am not sure why this would change all of the sudden. I updated VS2015 to the latest version and it still won't work.</p>
  <p>UPDATE:
  I put the InitializeComponent() call inside a try catch in an attempt to get the exception object and now the exception is not being thrown.</p>
  <pre><code>        try
          {
              InitializeComponent();
          }
          catch (Exception ex)
          {
              MessageBox.Show(ex.InnerException.Message);
          }
  </code></pre>
  <p>UPDATE 2:
  It is still throwing the exception, but &quot;catch (Exception ex)&quot; ignores TypeNameParserException for some reason.</p>