I followed all of the suggestions, and the Norton 360 app for MAC still won't open. I deleted all Norton 360 files and re-installed them - nothing changed. I clicked on the Live-Update in the display bar above - no cogwheel to indicate it was working and still not able to open the app. I updated my MacOS to Monterey 12.0.1 and still no change with opening the app.
Any more suggestions?