Can you try the following:
- remove all stuff in your jukebox folder (users/shawn/desktop/jukebox)
- start YamJtoMede8er again. Is it now starting without any error?
- set now movie folder to scan in yamj settings and then run again
- if you than exit it and start it again and if gives again the error than something is wrong with one or more of your movie folder names or names of your media files.
Advise regarding naming movie folders:
- give them the same name as you find them in
www.imdb.comAdvise regarding naming of media files like .mkv and avi
- give them the same name as found in
www.imdb.com, so e.g. Avatar (2009).mkv