"An authentication error occurred. The function requested is not supported. The remote computer is xxx.xxx.xxx.xxx. The cause of the error may be ..."
The error appears when connecting to a remote desktop (RDP), if updates related to the CredSSP encryption fix are not installed on it. To restore connectivity, you can disable the encryption check in the registry.
REG ADD HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\System\CredSSP\Parameters\ /v AllowEncryptionOracle /t REG_DWORD /d 2