For Kerio Control hardware appliances:
If the UI is unresponsive or the filter refuses to activate despite a valid license, a service restart via SSH or the local console often resolves the "stuck" state.
Test network and DNS
Verify time and certificates
Check subscription/license
Inspect outbound connectivity and firewall rules
Review SSL inspection / proxy settings
Restart categorization/update service
Clear cache / reset web filter settings
Reproduce and verify
If you manage a network using Kerio Control (now part of GFI Software), you rely on its web filtering capabilities to enforce acceptable use policies, block malware domains, and regulate bandwidth. So, it’s more than a little alarming when you log into the administration interface and see the dreaded red or orange alert:
"Web Filter is not activated. Categorization is disabled."
This error means that Kerio Control cannot connect to the cloud-based URL categorization service, or that the local database is corrupted/present. As a result, your firewall falls back to basic filtering or no filtering at all, rendering your security policies useless. For Kerio Control hardware appliances:
In this guide, we will explore why this error occurs and provide a step-by-step troubleshooting sequence to restore full web filtering functionality.
The categorization database is downloaded from GFI’s update servers. If your firewall blocks its own updates, you’ll see this error.
Test connectivity from the Kerio Control machine itself:
nslookup updates.gfi.com
curl -I https://download.kerio.com/control/categorization/latest.dat
Required outbound access (allow these in your firewall rules): If the UI is unresponsive or the filter
If Kerio Control is behind another upstream firewall, create an explicit allow rule from the Kerio Control’s own IP to those destinations.