Answer by Felipe Thomé for Could not find a part of the path ... bin\roslyn\csc.exe

On my case, i Noticed that the "build" folder was not present in "packages\Microsoft.CodeDom.Providers.DotNetCompilerPlatform.2.0.0" path. And that was the reason why the roslyn folder was not beeing created.

So the solution for me was:

1. Clean solution
2. Go to Nuget Package Manager
3. Uninstall Microsoft.CodeDom.Providers.DotNetCompilerPlatform
4. Clean solution
5. Install Microsoft.CodeDom.Providers.DotNetCompilerPlatform again from Nuget package manager.
6. Clean/Rebuild

And there you go. None of the solution above worked for me . Hope this helps anyone