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April 28, 2021—KB5001391 (OS Builds 19041.964 and 19042.964) Preview

Release Date:

4/28/2021

Version:

OS Builds 19041.964 and 19042.964

4/13/21
REMINDER
Microsoft removed the Microsoft Edge Legacy desktop application that is out of support in March 2021. On April 13, 2021, we installed the new Microsoft Edge. For more information, see New Microsoft Edge to replace Microsoft Edge Legacy with April’s Windows 10 Update Tuesday release

2/24/21
IMPORTANT As part of the end of support for Adobe Flash, KB4577586 is now available as an optional update from Windows Update (WU) and Windows Server Update Services (WSUS). Installing KB4577586 will remove Adobe Flash Player permanently from your Windows device. Once installed, you cannot uninstall KB4577586. For more details about Microsoft’s plans, see Update on Adobe Flash Player End of Support.

11/17/20

For information about Windows update terminology, see the article about the types of Windows updates and the monthly quality update types. To view other notes and messages, see the Windows 10, version 2004  update history home page.


Note Follow @WindowsUpdate to find out when new content is published to the release information dashboard.

 Highlights

  • Introducing news and interests on the Windows 10 taskbar

    With news and interests on the Windows taskbar, you get quick access to an integrated feed of dynamic content, such as news, weather, sports, and more, that updates throughout the day. You can personalize your feed with relevant content tailored for you. In the coming weeks, you will be able to seamlessly peek into your feed directly from the taskbar throughout your day without disrupting your workflow. For more information, see Personalized content at a glance: Introducing news and interests on the Windows 10 taskbar.

  • Updates an issue to prevent blank tiles from appearing on the Start menu after updating to a newer version of Windows 10. 

  • Adds the ability to adjust the amount of idle time before a headset goes to sleep in the Settings app for Windows Mixed Reality. 

Improvements and fixes

Note: To view the list of addressed issues, click or tap the OS name to expand the collapsible section.

  • 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.

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

  • This build includes all the improvements from Windows 10, version 2004.

  • No additional issues were documented for this release.

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

  • Addresses an issue that prevents a site from transitioning out of Microsoft Edge IE Mode when expected. 

  • Addresses an issue that fails to remove mandatory profiles completely when you sign out when using the “Delete cached copies of roaming profiles” Group Policy.

  • Addresses an issue that causes blank tiles to appear on the Start menu with names such as “ms-resource:AppName” or "ms-resource:appDisplayName". These blank tiles represent the installed applications and appear for approximately 15 minutes after updating to a newer version of Windows 10. Installing this update prevents these blank tiles from appearing on the Start menu.

  • Addresses an issue with the Microsoft Japanese Input Method Editor (IME) that prevents an app's custom candidate window from displaying correctly.

  • Addresses an issue that occurs when you install inventory applications.

  • Addresses an issue that includes kernel mode rules for .NET applications in Windows Defender Application Control policies. As a result, the generated policies are significantly larger than necessary.

  • Addresses an issue that causes devices to fail Device Health Attestation.

  • Addresses an issue that turns off S Mode when you enable System Guard Secure Launch on a system running Windows 10 in S Mode.

  • Addresses an issue that causes lsass.exe memory usage to grow until the system becomes unusable. This occurs when Transport Layer Security (TLS) resumes a session.

  • Addresses an issue with a race condition between Task Scheduler and the Workstation Service. As a result, users cannot automatically join a hybrid Azure Active Directory (AAD) domain and error 0x80070490 is generated. 

  • Addresses an issue that causes Azure Active Directory authentication to fail after signing in on Windows Virtual Desktop machines.

  • Addresses an issue that causes AAD Work Accounts to unexpectedly disappear from certain apps such Microsoft Teams or Microsoft Office.

  • Addresses an issue that accidently triggers hybrid AAD joining when the Group Policy “Register domain-joined computers as devices” is set to DISABLED. For more information, see Post configuration tasks for Hybrid Azure AD join

  • Addresses an issue with a partial Service Connection Point (SCP) configuration that causes dsregcmd.exe to stop working. This issue occurs because of a case-sensitive domain ID name comparison that occurs when joining a hybrid Azure Active Directory domain using single sign-on (SSO).

  • Adds the ability to adjust the amount of idle time before a headset goes to sleep in the Settings app for Windows Mixed Reality.

  • Addresses an issue that might generate a stop error when Docker containers run with process isolation.

  • Addresses an issue that causes automatic enrollment and certificate retrieval to fail with the error, “The parameter is incorrect.”

  • Addresses an issue that might cause Microsoft Defender Application Guard virtual machines to stop responding when Microsoft Defender Application Guard for Office opens a document. This issue might occur on some devices or in drivers that utilize GPU Hardware Accelerated Scheduling.

  • Addresses an issue that prevents some media players from playing content on hybrid devices that are running with dGPU on iGPU displays.

  • Addresses an issue with race conditions that cause high CPU usage. As a result, the system stops working and deadlocks occur.

  • Addresses an issue with a deadlock in the New Technology File System (NTFS).

  • Addresses an issue that causes DWM.exe to stop working in some cases.

  • Improves the Windows Server Storage Migration Service by:

    • Adding support for migration from NetApp FAS arrays to Windows Servers and clusters.

    • Resolving multiple issues and improving reliability.

      For more information, see Storage Migration Service overview.

  • Addresses an issue that might prevent an application screen from working when using a Remote Desktop ActiveX control that is embedded in an HTML page.

If you installed earlier updates, only the new fixes contained in this package will be downloaded and installed on your device.

Windows Update Improvements

Microsoft has released an update directly to the Windows Update client to improve reliability. Any device running Windows 10 configured to receive updates automatically from Windows Update, including Enterprise and Pro editions, will be offered the latest Windows 10 feature update based on device compatibility and Windows Update for Business deferral policy. This doesn't apply to long-term servicing editions.

Known issues in this update

Symptoms

Workaround

When using the Microsoft Japanese Input Method Editor (IME) to enter Kanji characters in an app that automatically allows the input of Furigana characters, you might not get the correct Furigana characters. You might need to enter the Furigana characters manually.

Note The affected apps are using the ImmGetCompositionString() function.

We are working on a resolution and will provide an update in an upcoming release.

Devices with Windows installations created from custom offline media or custom ISO image might have Microsoft Edge Legacy removed by this update, but not automatically replaced by the new Microsoft Edge. This issue is only encountered when custom offline media or ISO images are created by slipstreaming this update into the image without having first installed the standalone servicing stack update (SSU) released March 29, 2021 or later.

Note Devices that connect directly to Windows Update to receive updates are not affected. This includes devices using Windows Update for Business. Any device connecting to Windows Update should always receive the latest versions of the SSU and latest cumulative update (LCU) without any extra steps.

To avoid this issue, be sure to first slipstream the SSU released March 29, 2021 or later into the custom offline media or ISO image before slipstreaming the LCU. To do this with the combined SSU and LCU packages now used for Windows 10, version 20H2 and Windows 10, version 2004, you will need to extract the SSU from the combined package. Use the following steps to extract the using SSU:

  1. Extract the cab from the msu via this command line (using the package for KB5000842 as an example): expand Windows10.0-KB5000842-x64.msu /f:Windows10.0-KB5000842-x64.cab <destination path>

  2. Extract the SSU from the previously extracted cab via this command line: expand Windows10.0-KB5000842-x64.cab /f:* <destination path>

  3. You will then have the SSU cab, in this example named SSU-19041.903-x64.cab. Slipstream this file into your offline image first, then the LCU.

If you have already encountered this issue by installing the OS using affected custom media, you can mitigate it by directly installing the new Microsoft Edge. If you need to broadly deploy the new Microsoft Edge for business, see Download and deploy Microsoft Edge for business

A small subset of users have reported lower than expected performance in games after installing this update. Most users affected by this issue are running games full screen or borderless windowed modes and using two or more monitors.

This issue is resolved in KB5003690.

After installing this update, 5.1 Dolby Digital audio may play containing a high-pitched noise or squeak in certain apps when using certain audio devices and Windows settings.

Note This issue does not occur when stereo is used.

This issue is resolved in KB5003690.

After installing this update or later, the news and interests button in the Windows taskbar might have blurry text on certain display configurations.

This issue is resolved in KB5003690.

How to get this update

Before installing this update

Prerequisite:

Microsoft now combines the latest servicing stack update (SSU) for your operating system with the latest cumulative update (LCU). If you encounter the error, 0x800f0823 – CBS_E_NEW_SERVICING_STACK_REQUIRED, close the error message and install the last standalone SSU (KB4598481) before installing this LCU. You will not need to install this SSU (KB4598481) again for future updates. 

For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.

Install this update

Release Channel

Available

Next Step

Windows Update or Microsoft Update

Yes

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

Microsoft Update Catalog

Yes

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

Windows Server Update Services (WSUS)

No

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

If you want to remove the LCU

To 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 information

For a list of the files that are provided in this update, download the file information for cumulative update 5001391

For a list of the files that are provided in the servicing stack update, download the file information for the SSU - version 19041.963 and 19042.963

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