FortiClient VPN Connection Fails to Start and System Tray Icon Missing on Multiple Endpoints

Hello together,

we are currently using free FortiClient VPN in our environment and have started experiencing a serious issue affecting multiple users.

When users click “Connect” in the FortiClient VPN client, the connection progress does not start — no percentage counter appears and the login process does not proceed at all. In addition, the FortiClient icon is no longer visible in the system tray.

We have already:

Restarted all related services

Performed complete uninstallations and reinstallations

Rebooted the affected machines multiple times

None of these steps resolved the issue. The only thing that has worked so far is a full reinstallation of the operating system, which is obviously not a sustainable solution.

The issue has already occurred on 6 machines and the number is increasing.

We need assistance in identifying the root cause and a proper fix.

Thanks for the Help.

Ist an German Client.

There is no percentage progress bar displayed during the connection attempt. Additionally, when clicking “Disconnect”(in german: "Trennen") nothing happens and the client does not respond.