April 21, 2020—KB4550945 (OS Builds 18362.815 and 18363.815)

View products that this article applies to.

Release Date:

Apr 21, 2020

Version:

1903-OS Build 18362.815 and 1909-OS Build 18363.815

IMPORTANT We have been evaluating the public health situation, and we understand this is impacting our customers. In response to these challenges, we are prioritizing our focus on security updates. Starting in May 2020, we are pausing all optional non-security releases (C and D updates) for all the supported versions of Windows client and server products (Windows 10, version 1909 down to Windows Server 2008 SP2).

There is no change to the monthly security updates (B release – Update Tuesday); these will continue as planned to ensure business continuity and to keep our customers protected and productive.

What's new for Windows 10, version 1909 and Windows 10, version 1903 release notes

Windows 10, versions 1903 and 1909 share a common core operating system and an identical set of system files. As a result, the new features in Windows 10, version 1909 were included in the recent monthly quality update for Windows 10, version 1903 (released October 8, 2019), but are currently in a dormant state. These new features will remain dormant until they are turned on using an enablement package, which is a small, quick-to-install “master switch” that simply activates the Windows 10, version 1909 features.

To reflect this change, the release notes for Windows 10, version 1903 and Windows 10, version 1909 will share an update history page. Each release page will contain a list of addressed issues for both 1903 and 1909 versions. Note that the 1909 version will always contain the fixes for 1903; however, 1903 will not contain the fixes for 1909. This page will provide you with the build numbers for both 1909 and 1903 versions so that it will be easier for support to assist you if you encounter issues.

For more details about the enablement package and how to get the feature update, see the Windows 10, version 1909 delivery options blog.

For more information about the various types of Windows updates, such as critical, security, driver, service packs, and so on, please see the following article.

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

↑ Back to the top

Highlights

Updates an issue that prevents certain apps from opening after you upgrade from a previous version of Windows, and a Bad Image error message appears.
Updates in an issue that turns off notifications for devices that use a virtual private network (VPN) on a cellular network.
Updates an issue that prevents you from resuming a Microsoft Xbox game on a Windows device after upgrading from a previous version of Windows.
Updates an issue that causes a text box that contains multiple lines of text to stop responding in certain scenarios.
Updates an issue that generates unexpected notifications when you change the default application settings.
Updates an issue that causes Windows Update to stop responding when you check for updates.
Updates an issue that fails to print content that is outside of the margins of a document.

↑ Back to the top

Improvements and fixes

Windows 10, version 1909

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

This build includes all the improvements from Windows 10, version 1903.
No additional issues were documented for this release.

Windows 10, version 1903

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

Addresses an issue that prevents certain apps from opening after you upgrade from a previous version of Windows, and a Bad Image exception dialog box appears.
Addresses in an issue that turns off notifications for devices that use a virtual private network (VPN) on a cellular network.
Addresses an issue that prevents you from resuming a Microsoft Xbox game on a Windows device after upgrading from a previous version of Windows.
Addresses an issue that causes a box that contains multiple lines of text to stop responding in certain scenarios.
Addresses an issue that prevents the touch keyboard from appearing during sign in when the user is prompted for the password.
Addresses an issue that prevents the touch keyboard from opening in Universal Windows Platform (UWP) apps when USB devices are connected.
Addresses an issue that displays incorrect folder properties in File Explorer when the path is longer than MAX_PATH.
Addresses an issue that prevents the correct lock screen from appearing when all of the following are true:
- The Group Policy Object (GPO) policy "Computer Configuration\Windows Settings\Security Settings\Local Policies\Security Options\Interactive Logon: Do not require Ctrl+Alt+Del Computer" is disabled.
- The GPO policy “Computer Configuration\Administrative Templates\System\Logon\Turn off app notifications on the lock screen” is enabled.
- The registry key HKLM\SOFTWARE\Policies\Microsoft\Windows\System\DisableLogonBackgroundImage is set to 1.
Addresses an issue that generates unexpected notifications related to changing the default application settings.

Addresses an issue that causes the sign in screen to be blurry.
Addresses an issue that causes Windows Update to stop responding when you check for updates.
Addresses an issue that prevents the Sign in options page from opening using the ms-settings:signinoptions-launchfingerprintenrollment Uniform Resource Identifier (URI).
Addresses an issue with Bluetooth group policy settings on Microsoft Surface Pro X devices.
Addresses an issue that causes a KERNEL_SECURITY_CHECK_FAILURE (139) stop error when Windows resumes from Sleep and turns on certain Bluetooth headsets.
Addresses a reliability issue in WDF01000.sys.
Addresses an issue that causes an error in logman.exe. The error is, "A user account is required in order to commit the current Data collector Set properties."
Addresses an issue that prevents users from setting the REG_EXPAND_SZ keys in some automated scenarios.
Addresses an issue that causes a memory leak in the LsaIso.exe process when the server is under a heavy authentication load and Credential Guard is enabled.
Addresses an issue that causes the Trusted Platform Module (TPM) initialization to fail with system event error 14 and prevents Windows from accessing the TPM.
Addresses an issue that causes communication with the TPM to time out and fail.
Addresses an issue that prevents hash signing using the Microsoft Platform Crypto Provider for TPMs from working correctly. This issue might also affect networking software, such as VPN applications.
Addresses an issue that prevents applications running in an Azure Active Directory environment from receiving account change notifications. This occurs when using the Web Account Manager (WAM) and the WebAccountMonitor API.
Addresses an issue that causes systems to stop working with a 0x3B stop code when running a binary that is signed by a revoked certificate.
Addresses an issue with merging Windows Defender Application Control policies that sometimes generates a duplicate rule ID error and causes the Merge-CIPolicy PowerShell command to fail.
Addresses an issue that prevents a user’s PIN from being changed after connecting the device to Microsoft Workplace Join.
Addresses an issue that fails to print content that is outside of the margins of a document.
Addresses an issue that prevents Microsoft Internet Information Services (IIS) management tools, such as IIS Manager, from managing an ASP.NET application that has configured SameSite cookie settings in web.config.
Addresses an issue that causes Microsoft Edge to stop working if you attempt to use paste functionality on webpages when cut-and-paste functionality has been disabled using a policy and Windows Defender Application Guard is active.
Addresses an issue that causes the Clipboard service to unexpectedly stop working when signing out.
Addresses an issue that displays a black screen to Windows Virtual Desktop users when they attempt to sign in.

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.

↑ Back to the top

Known issues in this update

Symptom	Workaround
After installing this optional update, some devices might have licensing issues with apps and games installed from the Microsoft Store. On affected devices, apps might fail to open or close unexpectedly, premium content might be disabled, or you might receive an error message.	This issue is resolved. Please note that it can take up to 24 hours for the issue to resolve on your device. If you are still encountering the issue, you might see the issue resolved after restarting your device. For enterprise-managed devices that have installed this update and encountered this issue, it can be resolved by installing and configuring a special Group Policy. To find out more about using Group Policies, see Group Policy Overview.
After installing this update on a Windows 10 device with a wireless wide area network (WWAN) LTE modem, reaching the internet might not be possible. However, the Network Connectivity Status Indicator (NCSI) in the notification area might still indicate that you are connected to the internet.	This issue is resolved in KB4559004.

↑ Back to the top

How to get this update

Before installing this update

Microsoft strongly recommends you install the latest servicing stack update (SSU) for your operating system 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 (KB4552152) 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 4550945.

Note Some files erroneously have “Not applicable” in the “File version” column of the CSV file. This might lead to false positives or false negatives when using some third-party scan detection tools to validate the build.

↑ Back to the top