Symantec AV definition file

We use Symantec AV for our corporate PCs. Often users get an “virus definition file is more than 10 days old” error.

I can solve this locally as admin but the big picture is that I want this to update automatically and without error. Some PCs are perfectly fine but I get 3 0r 4 a week that suddenly show the error.

Can anybody advise if this is a config or parent server issue? or might have suggestions on how to solve for good?