Silverlight projects stopped compiling under “Any CPU” option

Question

I have an x64 build server that has been compiling Silverlight projects for a long time without any issues. Then suddenly it started complaining "Silverlight 4 SDK is not installed" and now I can compile SL projects only under "x86" platform. I'd like to continue using "Any CPU" for all projects but I can't figure out what happened.

Answer 1

This issue is nearly always due to an incorrect invocation of the x64 version of MSBuild. Ensure that you are using the x86 version of the build tools.