Table of contents

Release Date:



OS Build 17784.1979

Improvements and fixes

This non-security update includes quality improvements. Key changes include: 

  • Addresses an issue that causes the Kubernetes cluster worker node to stop working, which affects the pods in K8s clusters. 

  • Addresses an issue that prevents Cluster Aware Updating (CAU) from updating the cluster. This issue occurs if CAU runs in mixed mode after a previous attempt to update the cluster.

  • Implements a Group Policy setting for the following registry value:

    Registry location:  HKLM\Software\Policies\Microsoft\Windows NT\Printers\PointAndPrint

    Value name: RestrictDriverInstallationToAdministrators

    Value data: 1

    For more information, see KB5005652.

  • Adds the ability to configure period or dot (.) delimited IP addresses interchangeably with fully qualified host names in the following Group Policy settings:

   To return to the Azure Stack HCI documentation site

Known issues in this update



After installing KB5005105, virtual machines (VMs) employing Software Defined Networks (SDN) or traditional multi-tenant RRAS gateways may lose connectivity with external networks using Gateway connections. Installing the August preview or later update will not affect HCI hosts, Network Controller VMs, and Software Load Balancer VMs.

This issue is resolved in KB5006679.

How to get this update

The September 21, 2021 preview update (KB5005620) for Azure Stack HCI is delivered from the release channels below. To install it on your Azure Stack HCI cluster, see Update Azure Stack HCI clusters.

Install this update

Release Channel


Next Step

Windows Update and Microsoft Update


Go to Settings Update & Security > Windows Update. In the Optional updates available area, you’ll find the link to download and install the update.

Windows Update for Business


None. These changes will be included in the next security update to this channel.

Microsoft Update Catalog


To get the standalone package for this update, go to the Microsoft Update Catalog website.

Windows Server Update Services (WSUS)


You can import this update into WSUS manually. See the Microsoft Update Catalog for instructions.

File Information

For a list of the files that are provided in this update, download the file information for cumulative update 5005620.

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