The file name specified already exists in the project. This error has the following cause and solution:
When you rename a file that is shared by many different projects, the name of the file changes in all the projects that are sharing it. If any one of these projects already has a file with the same name, you create an ambiguous and invalid situation: two files in the same project with the same name. The Rename operation then fails.
To correct this, select another name for the file.