Kerio Control Web Filter Is Not Activated Categorization Is Disabled Work [extra Quality] -

That night, Leo didn't turn the filter back on. Instead, he wrote a 17-line script. It didn't enable categorization. It did something smarter. He set Kerio to a "Log-Only" mode with a custom rule: If categorization is disabled, then throttle all un-categorized traffic to 1kbps and route it to a local cache that updates every 10 seconds.

Once the web filter is active again, implement these best practices:

A trial license includes web filtering, but it expires. Many admins forget to update after a trial.

The Web Filter requires a specific active license module. If your core license is valid but the filter is "not activated," it may be a module-specific expiration. That night, Leo didn't turn the filter back on

Alternatively, use (depending on version):

nslookup categorization.gfi.com

Kerio Control does not rely solely on static blocklists. Instead, it uses . When a user requests a website, the Kerio appliance queries a remote categorization server (provided by Kerio’s parent company, GFI Software, or a third-party partner like McAfee). The server returns a category ID (e.g., 92 for “Gambling”). The appliance then applies your content rules. It did something smarter

If you are still experiencing issues, the Security Log provides the exact reason for the failure. Go to > Security . Look for errors mentioning "zvelo" or "web filter."

On rare occasions, the web filter module fails to install correctly. Backup your configuration ( Configuration → Backup → Download ), then reinstall Kerio Control. Restore the backup and reapply the license.

Sometimes, internal security rules inadvertently block the firewall's own outbound update traffic. Navigate to . Many admins forget to update after a trial

Did this error start happening ?

The most common reason for categorization being disabled is a licensing issue. The "Kerio Control Web Filter" (formerly Sophos or integrated categorization) requires an active subscription.