Remote Desktop Connection - An Authentication Error Has Occurred


Cannot connect to Windows Sever 2016 machines (Hyper-V VMs) via Remote Desktop. The same error occurs when trying to connect locally via Hyper-V Manager.

Remote Desktop Connection
An authentication error has occurred.
The function requested is not supported
Remote Computer: <Computer Name>
This could be due to CredSSP encryption oracle remediation.
For more Information, see

Disable MS Outlook Junk Mail filtering via Group Policy

To disable Junk Mail feature in Outlook 2010 add following registry entry on client computers via Group Policy (User Configuration > Preferences > Windows Settings > Registry)

  • Action: Update
  • Key Path: Software\Policies\Microsoft\Office\14.0\Outlook
  • Value Name: DisableAntiSpam
  • Value Type: REG_DWORD
  • Value Data: 1

Setup L2TP / IPSec VPN on Windows Server 2016

Following tutorial shows how to setup Windows Server 2016 (single NIC, behind NAT/Firewall) as a L2TP / IPSec VPN Server.

Install Remote Access Role

  • Open Server Manager > Manage > Add Roles and Features and add Remote Access role.
  • On Role Services screen choose only DirectAccess and VPN (RAS).

Cannot delete legacy mailbox on Exchange 2010 - Access is Denied


Some mailboxes on Microsoft Exchange 2010 cannot be deleted via Exchange Management Console. Following error is displayed:

Active Directory operation failed on <domain controller>. This error is not retriable. Additional information: Access is Denied. Active directory response: 00000005: SecErr: DSID-033520B4, problem 4003 (INSUFF_ACCESS_RIGHTS), data 0

The affected mailboxes seem to be those that were moved during Exchange Upgrades from Exchange 2003 > 2007 > 2010.


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