You Recieve Connection Closed when connecting from Fortigate VPN SSL to Windows Server RDP 2012/2016/2019/2022

Scenario:

You configured SSL VPN access through Fortigate (Either V6 or 6.5) and you configured a bookmark RDP connection, when connecting to servers you receive error Connection closed although traffic is allowed to the server via policy and RDP connection works localy

Solution:

Configure Group Policy to allow Encryption Oracle Remediation seto to vulenrable, older versions from FGT doesn’t support remediate option.

How to configure the GPO:

Computer Configuration -> Administrative Templates -> System -> Credentials Delegation then set Encryption Oracle Remediation to Vulnerable.