Win7 remote Desktop prompt "an authentication error occurred." The solution to the "required function is not supported"

System environment:

Server: Windows Server 2012 R2

Client: Windows 7

In order to facilitate the management of the server, usually in the client remote desktop to the server, recently suddenly could not connect, reported "authentication error." the required function is not supported "error. When an error occurs, the first reaction is to check the server. In the end, it turns out that the error has nothing to do with the server, and the problem lies in the client system. The solutions are summarized as follows:

Method 1: uninstall the KB4343900 update patch. This patch is the culprit for the failure.

Method 2: modify the registry and add the following key:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\ SOFTWARE\ Microsoft\ Windows\ CurrentVersion\ Policies\ System\ CredSSP]

[HKEY_LOCAL_MACHINE\ SOFTWARE\ Microsoft\ Windows\ CurrentVersion\ Policies\ System\ CredSSP\ Parameters]

"AllowEncryptionOracle" = dword:00000002

Method 3: enter the Group Policy Editor to modify the value of "encryption Oracle correction". "computer configuration"-"Administrative template"-"system"-"credential allocation"-"encryption Oracle Correction"-"enabled"-"Protection level: vulnerable × ×".