April 22, 2021 - KB5001396 (OS Build 18363.1533) Preview
4/13/21
IMPORTANT Windows 10, version 1909 will reach end of service on May 11, 2021 for devices running the Home, Pro, Pro for Workstation, and Server SAC editions. After May 11, 2021, these devices will no longer receive monthly security and quality updates that contain protection from the latest security threats. To continue receiving security and quality updates, Microsoft recommends updating to the latest version of Windows 10
We will continue to service the following editions: Enterprise, Education, IoT Enterprise, and Nano Container images.
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.
2/16/21
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.
12/8/20
REMINDER Windows 10, version 1903 reached end of servicing on December 8, 2020. To continue receiving security and quality updates, Microsoft recommends that you update to the latest version of Windows 10. If you want to update to Windows 10, version 1909, you must use the Enablement Package
KB4517245 (EKB). Using the EKB makes updating faster and easier and requires a single restart. For more information, see
Windows 10, version 1909 delivery options.
11/19/20
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 1909 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 that causes blank tiles to appear on the Start menu with names such as “ms-resource:AppName” or "ms-resource:appDisplayName".
- Adds the ability to adjust the amount of idle time before a headset goes to sleep in the Settings app for Windows Mixed Reality.
- Updates an issue that generates a stop error when you delete a file or folder from locations that sync with Microsoft OneDrive.
Improvements and fixes
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 window activation that occurs when an owned window is removed.
- Addresses an issue with searching after you select File > Open in a 32-bit application. When you click in the search box, the application stops working.
- Addresses an issue with evaluating the compatibility status of the Windows ecosystem to help ensure application and device compatibility for all updates to Windows.
- 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 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 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 Azure Active Directory (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 generates a stop error when you delete a file or folder from locations that sync with Microsoft OneDrive.
- Addresses an issue with a deadlock in the New Technology File System (NTFS).
- 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.
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
Symptom |
Workaround |
System and user certificates might be lost when updating a device from Windows 10, version 1809 or later to a later version of Windows 10. Devices will only be impacted if they have already installed any Latest cumulative update (LCU) released September 16, 2020 or later and then proceed to update to a later version of Windows 10 from media or an installation source which does not have an LCU released October 13, 2020 or later integrated. This primarily happens when managed devices are updated using outdated bundles or media through an update management tool such as Windows Server Update Services (WSUS) or Microsoft Endpoint Configuration Manager. This might also happen when using outdated physical media or ISO images that do not have the latest updates integrated.
Note Devices using Windows Update for Business or that connect directly to Windows Update are not impacted. Any device connecting to Windows Update should always receive the latest versions of the feature update, including the latest LCU, without any extra steps. |
If you have already encountered this issue on your device, you can mitigate it within the uninstall window by going back to your previous version of Windows using the instructions here. The uninstall window might be 10 or 30 days depending on the configuration of your environment and the version you’re updating to. You will then need to update to the later version of Windows 10 after the issue is resolved in your environment. Note Within the uninstall window, you can increase the number of days you have to go back to your previous version of Windows 10 by using the DISM command /Set-OSUninstallWindow. You must make this change before the default uninstall window has lapsed. For more information, see DISM operating system uninstall command-line options.
We are working on a resolution and will provide updated bundles and refreshed media in the coming weeks. |
Scroll bar controls might appear blank on the screen and not function after installing this update. This issue affects 32-bit applications running on 64-bit Windows 10 (WOW64) that create scroll bars using a superclass of the USER32.DLL SCROLLBAR window class. This issue also affects HScrollBar and VScrollBar controls that are used in Visual Basic 6 applications and the classes derived from System.Windows.Forms.ScrollBar that are used in .NET Windows Forms applications. A memory usage increase of up to 4 GB might occur in 64-bit applications when you create a scroll bar control.
Scroll bars you create using the SCROLLBAR window class or using the WS_HSCROLL and WS_VSCROLL window styles function normally. Applications that use the scroll bar control that is implemented in COMCTL32.DLL version 6 are not affected. This includes .NET Windows Forms applications that call Application.EnableVisualStyles(). |
Microsoft is working on a resolution and will provide an update in an upcoming release. |
How to get this update
Before installing this update
Prerequisite:
You must install the April 13, 2021 servicing stack update (SSU) (
KB5001406) or the latest SSU (
KB5003155) before installing 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.
If you are using Windows Update, the latest SSU will be offered to you automatically. To get the standalone package for the latest SSU, search for it in the
Microsoft Update Catalog.
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. |
File information
For a list of the files that are provided in this update, download the
file information for cumulative update 5001396.