They seem random however most of the times i remember them happening was after closing the stock player and switching to the open player.
That being said i have had omp crash when opening shortly after boot up i repeated the process but it didn't crash again could have been that mafw wasn't ready or something like that.

Also i cant remember if you said you fixed opening files from filebox or not but at the moment its broken and will split windows if you had the music section open (artist/albums/etc..) before trying to open a file.
however if the file was loaded with the stock player it will play fine in the open player

Thanks for the pointers on the logs will keep a constant one see if it has any useful information when i have a crash next.