Fix: An Authentication Error has occurred (Remote Desktop)

People using Remote Desktop Connection might face a situation where they experience the error “An Authentication Error has occurred” when trying to establish a connection with another remote PC. Microsoft has officially acknowledged the error message and even released a document stating the root and causes of the error.

This error message is not new and has been there in Windows for quite some time. This is because the causes of this error message can be tracked ranging from incomplete updates to problems in the group policy.

What causes ‘An Authentication Error has occurred’ while connecting to a Remote Desktop?

Like mentioned before, the causes for this error can be traced to a number of different modules. The causes are but not limited to:

• Latest updates are not installed in either the connecting computer or the target computer. The mismatch causes the remote desktop to abort.
• There are some problems in the group policy editor. Some Group Policy keys might need to be changed in order to grant access.
• There is a real password mismatch while connecting to the target computer.

Before you move on to the solutions, make sure that you have an active internet connection and are logged in as an administrator.

Solution 1: Installing Latest Windows Updates on both computer.

Before we move on to other extensive solutions, it is probably wise to install the latest Windows updates on both computers. When you are attempting to remotely connect, it is necessary that both the computers have the same security patches installed to avoid security vulnerabilities. These security patches are installing through Windows Updates.

1. Press Windows + S, type “update” in the dialogue box and open the application.
2. Once in Update settings, click on Check for updates.
3. Now Windows will connect to its server and after downloading the required files, will install the updates.

4. Make sure that both computers are updated. Restart your computer and check if the error message is resolved.

Solution 2: Making changes in Group Policy Editor

The Windows Group Policy Editor contains critical information which dictates how computers should interact and perform different operations. It is kind of guideline and it may vary computer to computer depending on preferences. There are some keys which we must change so a connection to the other computer is established without any issues.

1. Press Windows + R, type “gpedit.msc” in the dialogue box and press Enter.
2. Once in the Group Policy Editor, navigate to the following key:

Computer Configuration > Administrative Templates > System > Credentials Delegation > Encryption Oracle Remediation

3. Now open the key Encryption Oracle Remediation and change its status to Enabled. Also, set the Protection level to Vulnerable.

4. Press Apply to save changes and exit by pressing OK. Now check if the error message is resolved.

If you do not have Group Policy Editor on your computer, we can use the registry editor to add the key.

1. Press Windows + S, type “command prompt” in the dialogue box, right-click on the application and select Run as administrator.
2. Once in elevated command prompt, execute the following command:

REG ADD HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\System\CredSSP\Parameters\ /v AllowEncryptionOracle /t REG_DWORD /d 2

3. After executing the command, try connecting again. If this doesn’t work, restart your computer and try again.

In addition to the above solutions, you can also try:

• You can reset the password from the domain controller (for enterprises). Then from Active Directory, you can select the user and open its properties. Then in the tab Account, you can uncheck the option User must change password at next login.
• If you do not have access to the remote computer, you can remove the security update on the computer so both computers have the same version.
• Make sure that you are not restricted from connecting to the target computer. Same goes for the target if it is restricted from being connected with.
• Check your network’s Firewall.