December 14, 2021—KB5008218 (OS Build 17763.2366)

11/9/2021 IMPORTANT Because of minimal operations during the holidays and the upcoming Western new year, there won’t be a preview release (known as a “C” release) for the month of December 2021. There will be a monthly security release (known as a “B” release) for December 2021. Normal monthly servicing for both B and C releases will resume in January 2022.

11/17/20
For information about Windows update terminology, see the article about the types of Windows updates and the monthly quality update types. For an overview of Windows 10, version 1809, see its update history page.

Highlights

• Updates security for your Windows operating system.

Improvements and fixes

This security update includes quality improvements. Key changes include:

• Addresses a known issue that might prevent Microsoft Defender for Endpoint from starting or running on devices that have a Windows Server Core installation.
  If you installed earlier updates, only the new fixes contained in this package will be downloaded and installed on your device.For more information about the resolved security vulnerabilities, please refer to the new Security Update Guide website and the December 2021 Security Updates.

Windows 10 servicing stack update - 17763.2350

This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. Servicing stack updates (SSU) ensure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft updates.

Known issues in this update

__

Click or tap to view the known issues

Symptom	Workaround
After installing KB4493509, devices with some Asian language packs installed may receive the error, “0x800f0982 - PSFX_E_MATCHING_COMPONENT_NOT_FOUND.”

1. Uninstall and reinstall any recently added language packs. For instructions, see Manage the input and display language settings in Windows 10.

2. Select Check for Updates and install the April 2019 Cumulative Update. For instructions, see Update Windows 10.Note If reinstalling the language pack does not mitigate the issue, reset your PC as follows:

3. Go to the Settingsapp > Recovery.

4. Select Get Started under theReset this PC recovery option.

5. Select Keep my Files.
   Microsoft is working on a resolution and will provide an update in an upcoming release.
   After installing KB5001342 or later, the Cluster Service might fail to start because a Cluster Network Driver is not found.| This issue occurs because of an update to the PnP class drivers used by this service. After about 20 minutes, you should be able to restart your device and not encounter this issue.
   For more information about the specific errors, cause, and workaround for this issue, please see KB5003571.
   After installing updates released April 22, 2021 or later, an issue occurs that affects versions of Windows Server that are in use as a Key Management Services (KMS) host. Client devices running Windows 10 Enterprise LTSC 2019 and Windows 10 Enterprise LTSC 2016 might fail to activate. This issue only occurs when using a new Customer Support Volume License Key (CSVLK). Note This does not affect activation of any other version or edition of Windows. Client devices that are attempting to activate and are affected by this issue might receive the error, "Error: 0xC004F074. The Software Licensing Service reported that the computer could not be activated. No Key Management Service (KMS) could be contacted. Please see the Application Event Log for additional information."Event Log entries related to activation are another way to tell that you might be affected by this issue. Open**Event Viewer on the client device that failed activation and go toWindows Logs **>Application. If you see only event ID 12288 without a corresponding event ID 12289, this means one of the following:

• The KMS client could not reach the KMS host.
• The KMS host did not respond.
• The client did not receive the response.
  For more information on these event IDs, see Useful KMS client events - Event ID 12288 and Event ID 12289.| This issue is resolved in KB5009616.
  After you install this update on a server that is running Windows Server 2019, you might not be able to use Remote Desktop to reach the server. Eventually, the server might stop responding. Additionally, a black screen might appear, and signing in and general performance might slow.| This issue is resolved in KB5010196.
  After installing the November 22, 2021 or later updates, recent emails might not appear in search results in the Microsoft Outlook desktop app. This issue is related to emails that have been stored locally in a PST or OST files. It might affect POP and IMAP accounts, as well as accounts hosted on Microsoft Exchange and Microsoft 365. If the default search in the Microsoft Outlook app is set to server search, the issue will only affect the advanced search.| This issue is resolved in KB5010351.Alternate resolution if you have not installed updates dated February 8, 2022 or laterThis issue is resolved using Known Issue Rollback (KIR). Please note that it might take up to 24 hours for the resolution to propagate automatically to consumer devices and non-managed business devices. Restarting your Windows device might help the resolution apply to your device faster. For enterprise-managed devices that have installed an affected update and encountered this issue, you can resolve this by installing and configuring a special Group Policy (preferred).ImportantVerify that you are using the correct Group Policy for your version of Windows.Group Policy: Windows 10, version 1809, Windows 10 Enterprise LTSC 2019, and Windows Server 2019

How to get this update

Before installing this updateMicrosoft now combines the latest servicing stack update (SSU) for your operating system with the latest cumulative update (LCU). SSUs improve the reliability of the update process to mitigate potential issues while installing the LCU. For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.Prerequisite:You**must **install the August 10, 2021 SSU (KB5005112) before installing the LCU.Install this update****Release Channel	Available	Next Step
Windows Update and Microsoft Update	Yes	None. This update will be downloaded and installed automatically from Windows Update.
Windows Update for Business	Yes	None. This update will be downloaded and installed automatically from Windows Update in accordance with configured policies.
Microsoft Update Catalog	Yes	To get the standalone package for this update, go to the Microsoft Update Catalog website.
Windows Server Update Services (WSUS)	Yes	This update will automatically sync with WSUS if you configure Products and Classifications as follows:Product: Windows 10Classification: Security Updates

If you want to remove the LCUTo remove the LCU after installing the combined SSU and LCU package, use the DISM/Remove-Package command line option with the LCU package name as the argument. You can find the package name by using this command:DISM /online /get-packages.Running Windows Update Standalone Installer (wusa.exe) with the**/uninstall **switch on the combined package will not work because the combined package contains the SSU. You cannot remove the SSU from the system after installation.

File informationFor a list of the files that are provided in this update, download the file information for cumulative update 5008218.For a list of the files that are provided in the servicing stack update, download the file information for the SSU - version 17763.2350.