Thanks, Microsoft – CredSSP error when connecting to a terminal server

Halp ! My RDP connection can no longer connect.

Imagine doing your Windows updates, like a good boy, when suddenly you get this nice little error.

An authentication error has occurred.
The function requested is not supported.
Remote computer : <insert remote desktop server name>

This could be due to CredSSP encryption oracle remediation.
For more information, see https://go.microsoft.com/fwlink/?linkid=866660

What happened ?

Microsoft has patched a security thingie, recently on all recent server OS’es.
Every good citizen, using the default Remote Desktop software, has a big chance to be screwed.

Quick fix –>

Create a DWORD registry entry as follows :

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\CredSSP\Parameters] “AllowEncryptionOracle”=dword:00000002

Even more “lazy mode” –>

Download and unzip credssp file.

Doubleclick the REG file after unzipping.

No matter which solution you’ve chosen, reboot the client PC.