Try disabling and re-enabling the Web Filter to resolve activation issues.
For registration and database updates. UDP/TCP Port 53: For DNS resolution.
If you see "disabled" or "no license" , the fix above applies.
This step is a workaround for cases where DNS timeouts cause the system to falsely mark the web filter as unreliable. Instead of fixing the underlying DNS latency issue, it tells Kerio Control to ignore these timeouts. Try disabling and re-enabling the Web Filter to
If the configuration commands do not work, make sure the basic software configuration did not accidentally get turned off.
To fix the error, you must resolve underlying DNS resolution failures or modify the firewall's built-in reliability detection settings . This critical error completely stops web content filtering, allowing users to bypass company policies and browse unrestricted.
Older versions of Kerio Control hardcoded update URLs for categorization backends that may have been decommissioned or migrated by GFI Software. If you see "disabled" or "no license" ,
Kerio sends automated check queries to cloud infrastructure. If a response is dropped 10 consecutive times within 1 minute, the firewall marks the backend engine as unreliable and completely disables categorization.
If this error appears, it is usually due to one of four reasons:
Standard ISP or Google DNS servers (8.8.8.8) can cause authorization token failures for the domain *.zvelo.com . Redirecting these specific queries to faster public resolvers resolves the authentication loop. If the configuration commands do not work, make
Look at the or Primary DNS Server configured for the firewall firewall engine.
Kerio Control does not store the categorization parameters for millions of websites locally. Instead, it issues real-time, lightweight DNS queries to cloud databases. When this error occurs, it usually traces back to three primary failure points: