Trouble saving in 4.4.3 (unknown error)

I just downloaded the upgrade to 4.4.3, rebooted my system, and created a score. For reasons I don't understand, it is no longer saving changes. The last time this happened, it turned out the problem was an unrecognized character in the file name (a '?'). But in this instance, the file name is "The Three Girls.mscz"

The system has also captured a pair of unrecognizable files that seem to have been generated mid-process. Thoughts?