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

Cleaning my solution caused this problem with Visual Studio 2017. Unloading/reloading projects or more cleaning made no difference. Only thing that worked was closing and restarting Visual Studio.