The Kerio Connect Antivirus module can't be updated with the following Errors:
AntivirusModule.cpp: Antivirus Server error(0): Unable to fetch updates: Unknown_Error (-3000)
The license update can be failing with such log entries being generated:
License update failed: Automatic license update failed. User interaction is required by registration server
Kerio Connect installed on Windows Server 2008 R2 or Windows Server 2012
The mentioned Windows Servers are not using TLSv1.1 and TLSv1.2 as default HTTP protocols. The Kerio Connect Antivirus is dependant on Bitdefender server updates, that are using the TLS protocols mentioned above. This misalignment causes the Antivirus updates to fail because the HTTP connection can't be established.
GFI Licenses servers require a secure HTTP connection using modern TLSv1.1 and TLSv1.2 protocols.
Follow the procedure from the Microsoft Update to enable TLS 1.1 and TLS 1.2 article. It's recommended to install Service Pack 1 and the "Easy Fix" program.
Note: the Windows server reboot might be required upon completion.
Try to update Antivirus definitions
The Kerio Connect Antivirus is successfully updated.
The license update error is no longer showing in the logs.