Why do I get “An error occurred while validating. HRESULT = '80004005'” when building a setup project?

Question

Why do I get the following error when building a setup project?

An error occurred while validating. HRESULT = \'80004005\'

Answer 1

I have spent enormous time on this one myself, though none of the above worked. But I have found another solution with a registry hack, you need to add a new DWORD (EnableOutOfProcBuild) value of (0) to HKCU\SOFTWARE\Microsoft\VisualStudio\14.0_Config\MSBuild\EnableOutOfProcBuild

Note: this is for Visual Studio 2015