RDP CredSSP Error

Issue:

RDP Error:

An authentication error has occured. The function requested is not supported. This could be due to CredSSP encryption oracle remediation. For more information, see https://go.microsoft.com/fwlink/?linkid=866660

Workaround:

gpedit.msc - Computer Configuration - Administrative Templates - System - Credentials Delegation - change Encryption Oracle Remediation policy to Enabled, and Protection Level to Vulnerable.

Permanent Solution:

Ensure both client & server side have latest patch installed so that RDP can be established in a secure way. You can find the list of the corresponding KB number for each operating system here: https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/CVE-2018-0886