Fortigate 5.4 "(Rcode=-810, Hcode=-1004) (-20199)"

Solution 1:

I had the same issue with Fortinets SSLVPN-Client 4.0.2332 and our FortiGate with FOS6.2.1 since I have tried different Windows 10 "Onboard" SSL-VPN-Tools even from Fortinet itself. They did not behave as expected and therefore have been removed. Since then I ran into the same issue like you. I have tried to "repair" the SSLVPN-Client via the "Program and Features" menu of Windows10 (1903) and it worked instantly again - even without a reboot AND without Admincredentials! like Hope this is helpful for sombody.