title: Customising the default TFS Git build template
body: <p>I've saved the default TFS Git build template (<code>GitTemplate.12.xaml</code>) to a new Class Library project, fixed all the missing references and when I compile I get this:</p>
  
  <pre><code>C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Xaml.targets(347,5): 
  error XC1043: Extension 'Microsoft.Activities.Build.Validation.ValidationBuildExtension' 
  threw an exception of type 'System.Xaml.XamlObjectWriterException' 
    'The invocation of the constructor on type 
    'Microsoft.TeamFoundation.Build.Activities.Git.GitPull' that matches 
    the specified binding constraints threw an exception.'.`
  </code></pre>
  
  <p>Any help as to what could be wrong?</p>