I have no idea whether this has been discussed, but I am sharing my experience. So, for months I would try to do a full system scan, and only the live update and tune up would run. The full system scan would fail every time. Clicking on support after the scan failed once again today, I saw a suggestion to run a "quick scan" directly from the system tray instead of from the program. Instead of running a "quick scan" I ran "LiveUpdate" directly from the system tray and it was found that I needed a patch. I applied the patch (an option that is not given when trying to run a full system scan). After the patch was applied, I tried running a full system scan again, and it's working!!!
So, I said all of that to say this, if the full system scan fails, try running live update directly from the system tray to see if there is a patch that is needed. Apply the patch, and try running the full system scan again. 