Assembly reference not found in XAML, but code compiles when referenced in xaml.cs class

Question

I\'ve got a strange problem adding a dll reference. I\'ve got a WPF application and am trying to use the WPF MDI library: http://wpfmdi.codeplex.com/

As stated in th

Answer 1

I've finally solved the problem myself - going to leave this answer here incase someone has the same problem some time. Adding the solution itself to the reference path of the assembly solves the problem! It's a shame this isn't documented...

EDIT: To clarify, what I did was add the solution, rather than the dll. In other words, I added the MDI solution with all its classes. This naturally applies to DLLs where the source code is available too.