Ensure your Kerio Control is using reliable DNS servers (like 8.8.8.8 or 1.1.1.1) under Configuration > DNS . 3. Clear the Web Filter Cache
Check for updates and ensure you are running the most recent build compatible with your license. Summary Checklist Potential Cause Renew SMA or Web Filter subscription. Time Sync Issue Enable NTP and verify the correct Time Zone. DNS Failure Set Kerio to use 8.8.8.8 for system resolution. Server Timeout
If this fails, you may need to clear the cache via the console by deleting the contents of the /var/winroute/webfilter/ directory (advanced users only). 4. Firewall Rules and Port Access