This could be due to CredSSP encryption oracle remediation

[Window Title]
Remote Desktop Connection

An authentication error has occurred.
The function requested is not supported

Remote computer: <hostname or ip address>
This could be due to CredSSP encryption oracle remediation.
For more information, see


Solution 1:
This error appears after I’ve updated Windows. If you are update also the Server where you want connect this should be first and better solution. if you are connecting to a server of a Customer or 3rd party that you cannot update, you can use Solution 2.

Solution 2:
Open Local Group Policy Editor (executing gpedit.msc)
Navigate to Computer Configuration -> Administrative Templates -> System -> Credential Delegation
Double-click on Encryption Oracle Remediation the select Enabled and change Protection Level to Vulnerable click Apply then OK.