Some Correspondents have reported a problem when launching scripts for Catalina. The script doesn't launch and shows this error (screenshot from a Correspondent):
This was an issue that was reported several times during the beta period. I have been unable to replicate the problem myself on any Catalina installation. However, several users who reported it later found that—again, for unknown reasons—the issue eventually corrected itself.
It is baffling. The issue appears to occur during launch when the menu bar for the script is being populated. I'm keeping my eye on it, but, unfortunately, all I can recommend at this point is to check the script again after a few computer restarts.