Inevitable crash after lengthy edit of new score

This is hard to reproduce (as it takes days), but happens without fail every time.

I create and edit a new score, for a long time, usually days. I write it out pretty frequently. I try to close the score (from the per-score tabs) and the application crashes. I rarely lose work; it seemingly successfully closes the new file (I am careful to write it out before trying to close it), but the crash seems inevitable. This is with 2.0.1, Mac, latest Yosemite.