I Migrate my project to mvc 5.0 and razor engin 3 with Microsoft Instruction
But when open my solution Get this:
I Found The Problem, vs 2012 doesn't support it(see update section of this answer)
From Here said:
Unlike Razor V2 runtime and design time, VS2013 did not GAC these binaries. Instead, the binaries are installed in the project bin folder when corresponding NuGet package is installed, and in “%ProgramFiles (x86)%\Microsoft Visual Studio 12.0\Common7\IDE\CommonExtensions\Microsoft\Web\Razor\v3.0” to support design time.
So we don't have these dlls in above path when upgrade to mvc5 /razor 3
also read this stack question
update: now support it , update vs from here