From the logs (last line of your log) you learn that MWG cannot look up: [2015-12-04 18:57:50.419 +00:00] Cannot lookup host: tau.mcafee.com, it will be ignored.
That is bad, as this server is part of the update server infrastrucutre.
Go to troubleshooting > Network Tools
Enter tau.mcafee.com, click nslookup.
I think it won't resolve.
Check you DNS on the appliance. Pick the DNS servers you entered (if any) and try pining them.
If you cannot ping any, you have found your problem.