Strategy to diagnose Expression Blend 2 failure to open Window

I have a project with many WPF Windows. 1 particular Window doesn't open in Expression Blend 2. I would like to know what strategies i can use to diagnose and avoid the problem in future.

Most of the time, Blend 2 will display a window with an exception. I would then fix the problem causing that exception. However, this time, this is the exception i get.

Exception: Cannot create an instance of System.Windows.Window.
StackTrace: Empty 
InnerException: None

The program actually works fine. I want to use blend to view the windows and polish up some of the graphics. The only strategy i can think of at the moment is

• Remove Xaml markup to narrow down where its failing.

Is there any tip / trick or tool which can help me out ?

(I cant post code because its my company code. I cant make an example because my examples seem to load correctly in blend.)

Alas, i think there is no tricks i can use other than removing xaml code until i find the problem. I also would try viewing the xaml in visual studio 2008 just to verify that the xaml is really well formed.

Ho hum :(