Kerio Control Web Filter Is Not Activated Categorization Is Disabled Work Better May 2026

The Web Filter uses an external service (Zvelo) which requires a valid authorization token. These tokens expire every . If your DNS settings prevent the token from renewing, categorization will be disabled.

Kerio Control is designed to disable the Web Filter if it fails 10 consecutive DNS checks to reach the update servers within one minute. You can force it to ignore these failures and keep the filter active by using the SSH console.

: A full disk can prevent the license file from saving. Use SSH to check disk space and clear cache files in /var/lib/firebase if necessary. 4. Troubleshooting Miscategorized or Blocked Sites The Web Filter uses an external service (Zvelo)

If you are encountering the error your firewall has likely triggered a safety mechanism that pauses web filtering when it cannot reliably reach the categorization servers.

The Web Filter requires a specific active license; without it, the module behaves as a trial and will automatically disable after 30 days. Kerio Control is designed to disable the Web

If the filter is activated but still blocking legitimate sites, you can bypass the categorization engine for specific URLs. Using Kerio Control Web Filter

: Hold the Shift key while navigating to Status > System Health in the admin interface, then click Enable SSH . Use SSH to check disk space and clear

: Navigate to Configuration > DNS . Check Enable custom DNS forwarding and add a rule for *.zvelo.com to use Cloudflare (1.1.1.1) or OpenDNS (208.67.222.222) instead. 3. Fix Licensing and Activation Issues

Note: This will restart the Kerio Control service and may cause a brief internet interruption.