~ fwiw ~
Uninstall your Norton device security product on Mac here
Remove all Norton programs for Mac using the RemoveNortonMacFiles tool here
Message: “We are sorry. We are unable to download the support packages…” on Mac here
Message: “…You haven’t finished Setup and your computer is not protected…” on Mac here
Message: “Norton 360 is unable to continue. Please restart your Mac to stay protected…” here
Message: “At Risk: Your Vulnerability Protection definitions are not up-to-date. Your Mac may be at risk.” here