“Unspecified error” in Visual Studio 2008 when trying to view project properties

Question

When I set my active solution from Win32 to x64, I cannot build the project or view the properties.

When I try to build my project, it is skipped.

When I try

Answer 1

In my case removing TargetFrameworkVersion attribute from VisualStudioProject xml node of vcproj file solved the problem. I suspect it was caused by project file conversion from previous version of Visual Studio.