If you are trying to use Remote Desktop on your Windows and are encountering an authentication error. One of the most common errors is ‘An Authentication Error has occurred, the Function Requested Is Not Supported.’ If you’re seeing the same error, In this article, we will guide you through ways to fix the Remote Desktop authentication error on Windows

Method 1: Change the Remote Desktop Settings

To fix the “An authentication error has occurred” error, the first step you can take is to change the remote desktop settings.

Step 1: Press the Win key + R key at the same time to open the Run box.

Step 2: Type sysdm.cpl in the box and then click OK to open the System Properties window.

Step 3: Go to the Remote tab and then uncheck the Allow connections only from computers running Remote Desktop with Network Level Authentication (recommended) option. Click Apply and OK to save changes.

Step 4: Restart your computer and then check if the “An authentication error has occurred” error is gone.

Method 2: Change the Group Policy Settings

You can also try to change the Group Policy settings to fix the “An authentication error has occurred” error. Follow the detailed instructions below

Step 1: Open the Run box and then type gpedit.msc in the box. Click OK to open the Local Group Policy Editor window.

Step 2: Click Computer Configuration and then select Administrative Templates > System > Credentials Delegation on the left of the window.

Step 3: Double-click the Encryption Oracle Remediation on the right of the window.

Step 4: Choose Enabled and then select the Vulnerable option under the Protection Level drop-down menu. Click Apply and OK to save changes.

Step 5: Close all the windows. Type cmd in the Run box and then click OK to open the Command Prompt window.

Step 6: Type gpupdate /force in the window and then press Enter.

gpupdate /force

Step 7: Reboot your computer and then check if the error is fixed.

Method 3: Edit the Registry

There is another method you can try to fix the “An authentication error has occurred” error – edit the Registry.

Step 1: Type regedit in the Run box and then click OK to open the Registry Editor window.

Step 2: Navigate to HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionPoliciesSystemCredSSPParameters.

Step 3: Double-click the AllowEncryptionOracle DWORD to open its Edit DWORD window.

Step 4: Change the Value data to 2 and then click OK.

 

Step 5: Reboot your system then try again.

Conclusion

In our case after performing the above steps, we did not see the error again.

Hopefully, this article will be useful for you. Good luck!