If you don't have these files installed, you'll have error messages or other problems when loading some tracks.
Extract this .rar file to a temporary directory. Then copy the 2 .mas files that you'll find in \Common Maps Patch\Locations\ into your \GameData\Locations directory.
Now it should work.
Extract this .rar file to a temporary directory. Then copy the 2 .mas files that you'll find in \Common Maps Patch\Locations\ into your \GameData\Locations directory.
Now it should work.