FortiClient VPN only - not able to connect

Hello,

When I click on "connect" nothing is happening and the FortiClient VPN seems to be stuck. There is no error message coming up. I am trying to connect to a SSL VPN.

Installed the Client on different Mac computers and sometimes it works and sometimes it doesn't.

Anyone with the same issue and got a solution?

System environment:

FortiClient VPN only (6.4.6.1378) on macOS Mojave.

Regards