This was crazy and so was the solution for Norton 360 for Windows. Over several days, did all of the usual things, uninstall & reinstall - no help. Run the Norton Remove and Reinstall Tool in various iterations - no help. Used online help thru chat box where he manipulated my machine and did all the things I had done and a few more plus he ran windows update and moved me to windows 11 which I was avoiding. Well, if it works, okay, but still live update failed with the same error and autofix as usual was no help. He spent 6 hours on my machine with no solution! I was still getting Error 8921,253 with Live Update.
What did work strangely was reinstalling NordVPN, connecting to the Nord server, AND THEN LIVE UPDATE WORKED!
Why did this work is beyond me. When I previously uninstalled NordVPN several weeks ago, did that adversely affect my machine? Was that fixed on reinstallation?? Don't know, but I thought I would share this strange solution.