Kerio Control Web Filter Is Not Activated Categorization Is Disabled Fixed |top| Jun 2026

: Kerio Control obtains a Zvelo token that expires every 21 days. If DNS issues block the token refresh, the firewall logs an Invalid Authorization error.

The Kerio Control web filter is an essential feature that helps to protect networks from malicious and non-productive websites. When the web filter is not activated, and categorization is disabled, it can lead to security risks and decreased productivity. By following the steps outlined in this article, administrators can fix the issue and ensure that the web filter is working correctly. Regularly updating the Kerio Control software and categorization database can help to prevent such issues in the future.

Your own security rules might be blocking the web filter. The web filter needs access to specific IPs/domains. Go to .

This article provides a comprehensive guide to understanding, diagnosing, and fixing the "Kerio Control Web Filter is not activated" issue. What Does "Web Filter is Not Activated" Mean? : Kerio Control obtains a Zvelo token that

This troubleshooting guide explains why this error happens and provides step-by-step methods to fix it. Root Causes of the Error

Web Filter categorization disabled. Serial number: ko-197974

For Kerio Control hardware appliances:

If nothing works, reinstall the web filter module.

If after all these steps the problem persists, collect (Status → Support Bundle) and open a ticket with GFI Support – they can check if the internal categorization daemon fails to start due to a deeper system issue.

: To prevent future timeouts, they move away from ISP DNS and configure Custom DNS forwarding using reliable servers like Cloudflare (1.1.1.1) Disabling Reliability Detection When the web filter is not activated, and

If the filter remains disabled due to network instability, you can manually disable the "Reliability" check.

[Kerio Control Firewall] --(DNS Queries Overload/Blocked)--> [ISP DNS Server] | (Dropped Request) | [Cloud Database (Zvelo)]

When managing an enterprise network with , encountering the error "Kerio Control Web Filter is not activated, categorization is disabled" can severely expose your local network. This critical warning signifies that Kerio's cloud-based third-party content database (Zvelo) has stopped communicating with your firewall. Your own security rules might be blocking the web filter