Visual Studio warning about copies of files with different contents

Question

When I go to debug my C++ project in Visual Studio, up pops a little warning dialogue box that tells me:

A copy of datum.h was found in
c:/users/brad/desktop/sou         


        

Answer 1

This worked for me (as of March 2019):

1. Click the 'Build' drop-down menu in the top left of your Visual Studio window
2. Select 'Rebuild Solution'