Blend can’t locate types in external assemblies

While developing a Windows Store app I run into a Blend issue that caused me some headache.

I tend to define common converters in external assemblies in order to reuse them in other projects, so i added a reference to a Windows Store library project containing the converters I needed then swiched to Blend to use them from Create DataBinding dialog, and here’s what i got:

Problem: My library was not listed.

Really weird since here’s what I got doing the same from Visual Studio 2012

My MvvmHelper library is listed.

Using Visual Studio to add the assembly resulted in following Blend error:

Ok, i presume you probably want to know the reason (and how to fix it): The problem was caused by projects having different build configurations: that main project has a X86 configuration (required by Bing Maps component) while all referenced libraries where AnyCPU and looks like that Blend 2012 doesn’t like it.

Moving the entire solution to X86 solved the issue.

Blend team is working on having it fixed before Blend 2013 release.

Happy Blending!

Note: Many thanks to @unni for helping me on this.