I ran into this problem before & there’s a weird fix that I now don’t remember!! Live Update subscription has run out & there doesn’t seem to be a “place” to put new subscription number in (that’s even if I could get one!! Their – Symantec – customers svc. leaves something to be desired…).
I’m v. close to giving up (I posted on Symantec as well) & buying whole new program for six laptops…