When I upgraded to a recent version of Finale (not sure whether it was 25 or 26) I found that the desktop shortcut did not update and continued to point me to my former version, still on the machine. If I found the actual program in the Finder and clicked on it, it would open as expected.

This would be especially important on Catalina, which I do not think runs version 25 smoothly; so check to see if your desktop shortcut is pointing you towards the older version. (I eventually just got rid of the earlier version on my machine so that the new shortcut points to the correct version.

I am a little hazy about this since I do not often use my Mac for production work.

Are you sure that it's 26 that isn't opening? On my system, that's the behavior of 2014.5 which, of course, no longer works. Try opening directly from inside the Applications Folder in case the alias on your desktop is corrupted.

No error message? Hmmmm...

Is a bad internet connection interfering with the license server—might be MakeMusic's issue.

Open System Preferences/Security and unlock. See if the OS isn't allowing something to install. Clicking Open Anyway should fix this.

It won't open in Safe Mode but I do recommend booting into it then rebooting to rebuild corrupt pathways.

Try an OS reinstall. Boot with the Command r keys held down till you boot into the Repair Partition. From there, go to Reinstall OS. This will download and reinstall the OS and should include the recent Supplemental and Security Updates that came out a few days ago. Don't worry, this will not overwrite your data. Every now and then, I need to do this on a client machine. Do Not attempt Internet Recovery — this will restore your Mac to the way it came from Apple and overwrite your data.

This same problem is happening to me right now.

I was using 26.3 on OS High Sierra with no problems. I just upgraded to Catalina 10.15.6 and the Finale icon bounces in the dock. Fails to go past this stage. It shows up in the Force Quit window as Finale (not responding). (and now the icon is not bouncing in dock...just not responding).

I have done a few of the suggested steps like removing the fprf file from the Preferences. But nothing has changed this current reality.

Thanks for any thoughts/solutions!

Depending on your security settings, you probably need to add Finale as an approved app. Apple has support documents. Finale is not the only app that will have this issue. Had you run Mojave, you’d have already dealt with this.

If this support doc doesn’t address it exactly, Apple has others

https://support.apple.com/en-us/HT202491