If you are recently updates on Windows 10,8.1,2012 workstations or server in the MAY 2018 , you may face that you receive a particular issue when trying to connect a remote desktop connection to a server.This error is because of the latest Microsoft security updates.
An authentication error has occurred. The function requested is not supported Remote computer: <computer name>
This could be due to CredSSP encryption oracle remediation.
For more information, see https:/go.microsoft.com/fwlink/?linkid=866660
Unable to connect remote desktop connection RDP after Windows server updates CredSSP encryption oracle remediation in May 2018.
After May 2018 security update: RDP “An authentication error occurred” “This could be due to CredSSP encryption oracle remediation”.
How to fix this issue in single click.
Just download a file from given following link and after download extract it and run on remote server.
File download Link
If not work than you also need to update the client system as well with the same file and everything will work.
This works 100 % .
Second Method to fix it.
Aadd a single key to your workstation’s registry.
create the CredSSP key, then the Parameters key, then the dword value.