<File> is already in this project; you do not need to share it.

This warning has the following cause and solution:

• You can’t have two items in a project with the same name.  You are attempting to share a file into a project that already contains a file or subproject with the same name.

  If you would like the file to be in the project, you will either have to:

  • Rename the existing file/project before sharing the file into the project, or
    
    
  • Delete or destroy the existing item from the project