I am sure that everyone reading this (who has used Microsoft Expression Blend at least) has encountered the following error message:



You probably groan too when you see it. Where do you start looking … is it XAML related, or is it code …

Well, the answer is actually fairly simple. Debug blend.

Load the project in both Visual Studio and Blend.

Compile it in Blend.

In Visual Studio – attach the debugger to the running process of Blend – click Debug, Attach to Process and select Blend.

Now open the rough control / page / whatever in Blend.

And witness the exception (complete with details!) in Visual Studio.

Happy debugging :)