This was posted out by the guy who wrote the bliss application earlier. Some useful info about how to remove OSX system files which might be creating problems with the MMI player.
http://www.blisshq.com/music-library-management-blog/2015/05/05/dot_underscore_music_files/
http://www.blisshq.com/music-library-management-blog/2015/05/05/dot_underscore_music_files/