Kryton, believe us ;D Believe avast!
Believe avast! users 
Thanks techie for your praise words… 
I think Kryton that techie makes the goal: manual update. I do not use Kerio (but ZoneAlarm). But Kerio is a good firewall too and could handle avast! update. See if your “Kerio rules” do not avoid avast! update. I use a proxy and the port connected seem to be 8001 (Server: www.avast.com 66.98.166.72:8001). Sorry if I cannot help you more than this…