In the past, if RMM chokes while scanning your music, it was caused by a file someplace that's confusing it. Like an MP3 with a bunch of garbage in its tags or something.

The people working on RMM have tried very hard to prevent this situation from happening, so they are keen to ferret out any remaining bugs in this area. If you can locate a particular file that's causing the trouble, they might want to have a look at it and see why it's causing RMM to hang.