VS 2017 Metadata file '.dll could not be found

Question

I know there is another question with exact the same problem, but I went trough all those answers, and none helped me. :( (This was the question.)

I just created a new A

Answer 1

The problem was that I had some other normal error messages in my project, and apparently after I fixed those and when I cleaned and built my project AGAIN, then all .dlls succeeded.

Make sure you don't have any other error messages in your project and if you do, fix those first!