I also tried following steps from another post that recommended stopping the Services > Print Spooler.  That did not work either. Finale still opens, fails to completely load, and then shuts down.

Hmmmm..... interesting that you have not received any help on your post. I have Finale 26 and it will also not open. It just shows the opening window and that's where it freezes.

I am having the same problem now. I stopped the print spooler and it worked for one iteration. When I opened Finale 26 up again, same result.

Besides the print spooler, you can have a sound driver conflict. Keep in mind Finale 26 has worked and does work on thousands of computers. This almost proves it is a conflict on your machine. Finding It can be frustrating. 

Another one is a 'permissions' thing in Windows. You can create a new test account. Log on to that account and see if it allows Finale 26 to open.

Lastly or perhaps firstly make sure all your drivers are up-to-date. 

Although it may sound weird but your video driver can cause your sound driver to not respond in Finale. Make sure it is current too. All your drivers, need to be checked.

I have not downloaded anything new to the desktop.

I am assuming the OP is on a Windows machine. Claims to not have added any new apps. However, Windows probably did as it updates regularly all by itself.

I am also having the same issue with Finale 26 on Windows 10. I try to open a file or the application by itself and it just hangs until I force it to quit. The message next to the Finale icon in the top left says Finale (Not Responding). It used to work about a year ago, but not anymore. Any ideas?

Louis,

Do you have a clear path the the Finale>temp folder? If not make sure it is there. If you create it manually you must tell Finale where it is. Edit>Preferences> Folders

Ernest, I discovered that it is indeed the print spooler that is the issue. I also tried disabling various printers in the printer queue, but only stopping the spooler itself allows Finale to load. I am awaiting further direction from technical support regarding this. I will post anything new I find that solves the problem.