I'm sorry to hear you're having the same issue, but at the same time, a little happy that I'm not crazy.
Based on my experience and what you've said, this seems to point to a library setting issue. Initially, I thought uninstalling/reinstalling was the only way to resolve the issue. But it tuns out that as long as I have a backup of the library in it's last working state, I can restore it and get everyting working correctly again.
Note: that the uninstall/reinstall wasautomatically importing the settings from MC18, which is still on my machine). In fact hinking about it, I have inported the settings with each new version since MC14. I don't really tweak the settings too much except forsettings related to starting Theater Mode automatically at MC startup, as well as kernel streaming mode and play from memory.
The only other "weirdness" that I have in the mix is that I have JLAY installed on the machine. But I don't think that's an issue because the problem occurs when NOT using JPLAY for playback.
Still I think my next steps will be to:
1. Uninstall JPLAY
2. If JPLAY isn't the issue, I'm going to recreate my libary from scratch. (I'm wondering if some old setting that isne't applicable any more is in there or there's ome coruption of some sort in the imported library.
It may take me a couple of days to get around to this but I will post the outcome as soon as I do. In the meantime I'll responed to any replies to this post.
Thanks,
Dan