Well, the Noteworthy person wasn't so helpful, but I went exploring. I had installed Noteworthy 2.75 demo, thinking I could use my registration to change it to a paid version. That was blocked and didn't work. But when I uninstalled, I found a regular Noteworthy 2.75 version was also there. When I uninstalled the demo, the other version worked. I'm mystified, but relieved.
I tried Musescore and it looked like it might be good - but it has a learning curve, and I'm lazy. All of the MIDI files I've posted at Mudcat over the years, have been done on Noteworthy - I can do Noteworthy in my sleep.
So, I'm glad to be back to Noteworthy, with no upgrade charge. Maybe I shouldn't have gotten up in the middle of the night to post a MIDI. I was up for four hours....