Got another crash. This one happened on my 2012 Mini. It happened just as I went into the preferences panel and removed my external HD from the “Keep the library in sync with the following folders” list. The change took hold, when I went in to check the disk wasn’t on the list anymore.
Thanks for reporting these. If you are able to figure out a way to reproduce the crash(es) that would be very helpful. The crash report you linked is the same one as earlier; is there a different one?