Am running Norton Security ver 188.8.131.52. When it runs scheduled backup I get the attached error report. This just started to happen about a month ago.
You didn't mention which operating system you are using, but if you have not performed any restarts recently, I would start with that.
Initiate a few restarts spaced over a few hours. In between the restarts, manually run Live Update until there are no more updates left.
Please let us know how you do with that.