I've saved the default TFS Git build template (GitTemplate.12.xaml) to a new Class Library project, fixed all the missing references and when I compile I get this:
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.'.`
Any help as to what could be wrong?