It's a problem with "Make Backups when saving files". Turning this option off makes the error go away.
For future reference, make sure your preferences (Edit > Preferences > Folders) point to valid folders that already exist.
Yep, me neither... Preferences pointed to "Finale Files" in my OneDrive. Now, how about an error message that actually HELPS me fix that?!? Instead of Error Id moving file "s" to "s". Something lik...
Windows Finale v27.1.0.271