Vulnerability Signature corrupted file

System:  NAV Mac 11.0.3  OSX10.5.7      Norton Confidential 1.2.2

 

During normal usage this evening, we were prompted by our Mac to Restart (grey box overlayed on full screen video with power symbol in background with something about restart needed')

 

we did so and on rebooting, Norton then reports that the 'Vulnerability Protection Signatures are corrupted' and prompts a live update - we have done this but the same error comes up.  on trying to do the live update, the same grey box appears prompting a restart.

 

we have the downloaded version (non-disk) of NAV - what is the best way to go about clearing this error?

 

best regards

 

paul d