Norton 360 Deluxe, running on Windows 10 Pro x64bit, on November 12 -21 Windows updates ran now LiveUpdate stuck on Download protection updates. I tried canceling - nothing happens, at the top of the screen Update is canceling the update - but it doesn't nothing happens, screen is still there. No way to cancel or stop - checked Task Manager to see if I could cancel/stop, nothing listed to stop. I did a complete shutdown, power off, then powered back on, same thing happens now every time (I've tried few times same issue).
Start by doing a couple of system restarts to ensure those Windows updates get fully set up. Restart, not shutdown and startup again if you have Windows Fast Startup feature enabled. If you use Windows 8/8.1 or 10, there can be an issue with the Windows Fast Startup feature.. See more information here.
You might try doing a complete remove and reinstall. Download is in this link.
https://www.norton.com/nrnr