Overview

Some users may experience issues when trying to start the Kerio VPN client on their Windows 11 PC. Despite downloading and installing the latest client version, the service may not start. Additionally, the Kerio VPN service may not start in Services.msc. Users may also encounter an error (0x80071779) while trying to uninstall the Kerio Virtual Network adapter.

The Kerio Control VPN error logs may show entries like the below:

[04/Jan/2024 11:53:24] vpncore: Unable to initialize vpn core: unable to open VPN driver 
[04/Jan/2024 11:53:24] vpnMain: Unable to open VPN driver: Unknown error 
[04/Jan/2024 11:53:24] VpnFSM: Failed to initialize VPN driver (99).

And the Kerio Control VPN debug logs may show this:

[04/Jan/2024 11:55:48] {info} Kerio Control VPN Client Service 9.4.3 build 8353 started. 
[04/Jan/2024 11:55:48] {vpnCore} oldapi: KVpnInit() - ERROR 
[04/Jan/2024 11:55:48] {vpnCore} oldapi: KVpnStatusString() 
[04/Jan/2024 11:55:48] {engine} VpnFSM: GetStatus(). 
[04/Jan/2024 11:55:48] {info} Kerio Control VPN Client Service 9.4.3 build 8353 stopped.

Solution

To resolve this issue, follow these steps:

1. Make sure that you are running the latest Kerio Control VPN client version.
2. If you are using the latest version, it could mean that the VPN adapter is corrupt, and it requires manual cleaning.
3. Navigate to Device Manager > Network Adapter and Uninstall the Kerio Virtual Network Adapter. Alternatively, open Control Panel -> Network and Internet -> Network Connections -> right-click Kerio Virtual Network Adapter -> in Driver tab click Uninstall Device.
   
4. If you see WAN Miniport adapters, please uninstall all of them. It is normal if they are not being removed from the list after you uninstall. 
5. After deleting the adapter, proceed to Installing the Kerio Control VPN Client once more, which should run without issues

Summary

By following the steps outlined above, users should be able to resolve the issue of not being able to start the Kerio VPN client on their Windows 11 PC. If the problem persists, users are advised to contact support for further assistance.

FAQ

1. What if I still can't start the Kerio VPN client after following these steps?
   If the problem persists, please contact support for further assistance.
2. What does the error code 0x80071779 mean?
   This error code typically indicates a problem with uninstalling the Kerio Virtual Network adapter.
3. Can I manually delete the Kerio Virtual Network adapter?
   Yes, if you encounter an error while trying to uninstall the adapter, you can proceed to delete it manually from the Device Manager or Windows Control Panel