Try deleting all generated folders in your project directory. For example, .vs, Binaries, Intermediate, Saved, Source. I know you said you tried with just Saved and Intermediate but I have had a similar error before where I needed to delete all folders and then I could rebuild. I see that you are using Visual Studio 2015, you could try upgrading to 2017 if the problem persists. I wouldn’t think that would be a problem but who knows.