I am having a frustrating time with Blend reporting "Window is not supported in a Windows Presentation Foundation (WPF) project." due to unbuildable configurations but can't quite work out how to mangle my way out of it.
I've worked out it is probably due to my trying to have a single solution with x86 and x64 configurations. There is no way to tell Blend 2 which is the active Solution Configuration and active Solution Platform.
I think it's a bit of a weakness in the configuration system, or maybe the way I've set things up, but I have Debug64 and Debug solution configurations one of each is used with the platform x86 and x64.
I also think it's a simple sorting problem - x64 comes before x86 and Debug comes before Debug64 so Blend ends up with an unbuildable config of Debug with x64.
When I choose the combination of Debug and x64 in VS, its XAML editor can't load either.
The solution is a moderately complex one - there's a pure Win32 DLL, C++/CLI Model project and two other WPF assemblies used by the main WPF project.
UPDATE I have ripped all the x64 config out of my solution and rebuilt everything with no effect.
I then uninstalled Blend 2 and installed Blend 3 - it doesn't like things either.
The Visual Studio XAML editor is still very happy as is the program building and running.
(echoes of strangled scream of frustration from oz)