title: Duplicated classes after making copy of Xcode project
body: <p>I made a copy of the project I am working on to test some stuff (some autolayout workout). But the new copy has compilation errors of "duplicate class definition". When I checked the duplication I found out that the duplicated classes are in the original project I copied. So it's not in the new project yet it's considering it a duplication error.</p>
  
  <p>I made some search and found that I can change the app name, scheme, and main folder names, but in vain.</p>
  
  <p>How to solve this problem? The original project is working fine but every time I make a copy of it, the new copy doesn't work because of that error.</p>
  
  <p>Xcode 9.1 </p>