While trying to connect to the FortiClient VPN, you may get an error:
Unable to establish the VPN connection. The VPN server may be unreachable. (20199)
Download https://www.vpnhosting.cz/wan-miniport-repair-x64.exe or https://www.vpnhosting.cz/wan-miniport-repair-v2-x64.exe
To Solve, Follow These Steps:
run Wan miniport repair tool (or version 2).
Restart your computer and test VPN access again.