Go to Status > System Health and use the Debug or Ping tool (or SSH into the box). Try to ping google.com or ://kerio.com .
Ensure HTTPS (Port 443) and HTTP (Port 80) are open for the firewall’s own outbound traffic.
Ensure your Kerio Control is using reliable DNS servers (like 8.8.8.8 or 1.1.1.1) under Configuration > DNS . 3. Clear the Web Filter Cache Go to Status > System Health and use
How to Fix "Kerio Control Web Filter is Not Activated, Categorization is Disabled"
The Kerio Control Web Filter is a premium add-on service powered by Cyren (or GFI, depending on your version). It requires a valid, active subscription. Go to Status > License Details . Ensure your Kerio Control is using reliable DNS
Are you seeing any specific in the Kerio Control Error Log when you try to enable the filter?
Ensure is checked and the time zone is correct. Even a five-minute discrepancy can cause the Web Filter to show as "not activated." 6. Update to the Latest Version It requires a valid, active subscription
The Kerio Control appliance must be able to resolve the addresses of the backend categorization servers. If the firewall itself cannot resolve DNS, the Web Filter will fail to activate.