Unable to do a scan

I have been having an issue on two of my pc's that both run windows 8.1(64bit)

 

Every few day's they will not allow a quick or full scan manually run, and it sometime will say last updated 1 day ago.

 

Now I normally find this can be resolved just by closing down and restart, But sometimes this will not resolve the issue and no matter how many time you restart, it will not scan.

 

Now today I stumbled onto a way of restoring the scan back when it's being stubborn after trying a restart.

 

I  restart in safe mode, then shutdown and  restart as normal, and the scans are restored.

 

I thought I would post this info so that somebody who knows about these things might understand what is happening and possably help others with this issues.

 

I do not have any other security software running on the pc's only NIS.

 

Hope this is of help

 

Thanks Guy's