I tried to open a TFS 2010 build template within the Visual Studio shell (the bit that gets installed when you put Team Explorer onto a PC) and saw the error “The document contains errors that must be fixed before the designer can be loaded”.
”
At the bottom of the screen it showed that all the underling assemblies could not be found.
The solution is simple, install a ‘real version’ of Visual Studio, I put on Premium. It seems that the shell does not provide all the assemblies that are needed. Once I did this I could edit the XAML with no problems