Excellent addon! After doing some stuff through windows I got it working correctly without any issues,here's what you do:
Search for folder options, and open Control Panel’s Folder Options tool (called File Folder Options in some versions of Windows). Click the View tab, and check Always show icons, never thumbnails.
This will disable the making of hidden files such as thumbs.db,and any album cover art related to the music itself
After you do that,tick "show system files" and go into your music folder,and delete the jpg and thumbs.db files there,if you did everything correctly,they should be removed without any issues,after you've done that,you can untick the "show system files" option and play with this mod correctly