Uninstall your Norton device security product on Mac here
Remove all Norton programs for Mac using the RemoveNortonMacFiles tool here
Download and install your Norton device security product on Mac here
Fix problems opening Norton device security product for Mac 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