Event Error: 1001 Unable to download the current signature

Hello there,

Perusing the Event viewer on our Enterprise Console server I noticed the following errors  repeated every hour in the Application folder:

Error 1013 - Failure processin repository provider (Unable to download the current signature)

Error 1001 - Unable to download the current signature (The remote name could not be resolved: 'nacsigdefupdate.sophos.com')

The Source is the Sophos NAC. We don't use it, but I would like to know what is causing these and how I can stop them as they are filling up the events.

I have attached a copy of our Application Events for reference. You will need to change the extension back to .evt to view it properly.

Thanks for you help.

Damon