Deleting the preference files fixed the problems. But, wow, what a hassle getting everything back to the way it was. There are settings that I had completely forgotten I'd ever changed.

The DAW plugin also seems to have stopped working. At least, it used to work fine in Luna. Now it takes almost 10 minutes to open a song in my DAW and the sounds are all incorrect (I suspect it can't find the RealTracks and RealDrums but I've check the paths and those are correct.)