If you install KB5027271 on a Windows Server 2012 R2 Domain Controller, this can stop you from being able to log in remotely via RDP.
To fix this, I uninstalled the update.
I’ve run into other updates with this same issue recently, and I can’t help but wonder if the effort that went into testing update KB5027271 wasn’t that great, since the OS is going EOL in 10/10/23…