Microsoft releases Windows 10 build 19042.844 with tons of fixes

Windows 10 logo and laptop showing the Start Menu

Today, Microsoft is releasing a new cumulative update for those that are on Windows 10 version 20H2 or 2004, which are currently the newest versions of the OS. This is considered to be a "C" week release (even though it's actually the D week), which means that it's optional. When you check for updates in Windows Update, you'll be given the option to take this update.

The update that you're going to get is KB4601382, and it brings the build number to 19042.844 or 19041.844, depending on if you're on version 20H2 or 2004, respectively. You can manually download it here, and these are the highlights:

Updates an issue that displays unexpected screens during the Windows Out of Box Experience (OOBE).

Updates an issue in Advanced display settings that shows the incorrect refresh rates available for high dynamic range (HDR) displays.

Updates an issue that might cause video playback to flicker when rendering on certain low-latency capable monitors.

Updates an issue that sometimes prevents the input of strings into the Input Method Editor (IME).

Updates an issue that might sometimes prevent some keyboard keys from working, such as the home, Ctrl, or left arrow keys. This issue occurs when you set the Japanese IME input mode to Kana.

Updates an issue that displays the wrong language when you sign in to a console after you change the system locale.

Updates an issue with screen rendering after opening games with certain hardware configurations.

Displays the proper Envelope media type as a selectable output paper type for Universal Print queues.

Updates support for hole punch and stapling locations for print jobs with long edge first paper feed direction on certain printers.

Here's the full list of fixes:

Addresses an issue with a memory leak in Internet Explorer 11 that occurs when you use the Chinese language pack.

Addresses an issue with certain COM+ callout policies that cause a deadlock in certain applications.

Addresses an issue that prevents certain Win32 apps from opening as a different user when you use the runas command.

Addresses an issue that displays unexpected screens during the Windows Out of Box Experience (OOBE).

Addresses an issue that might cause a deadlock when a COM server delivers an event to multiple subscribers in parallel.

Addresses an issue in Advanced display settings that shows the incorrect refresh rates available for high dynamic range (HDR) displays.

Addresses an issue that might prevent certain CAD applications from opening if those applications rely on OpenGL.

Addresses an issue that might cause video playback to flicker when rendering on certain low-latency capable monitors.

Addresses an issue that sometimes prevents the input of strings into the Input Method Editor (IME).

Addresses an issue that exhausts resources because Desktop Windows Manager (DWM) leaks handles and virtual memory in Remote Desktop sessions.

Addresses an issue with a stop error that occurs at startup.

Addresses an issue that might delay a Windows Hello for Business (WHfB) Certificate Trust deployment when you open the Settings-> Accounts-> Sign-in Options page.

Addresses an issue that might sometimes prevent some keyboard keys from working, such as the home, Ctrl, or left arrow keys. This issue occurs when you set the Japanese IME input mode to Kana.

Removes the history of previously used pictures from a user account profile.

Addresses an issue that displays the wrong language when you sign in to a console after you change the system locale.

Addresses an issue that causes the host process of Windows Remote Management (WinRM) to stop working when it formats messages from a PowerShell plugin.

Addresses an issue in the Windows Management Instrumentation (WMI) service that causes a heap leak each time security settings are applied to WMI namespace permissions.

Addresses an issue with screen rendering after opening games with certain hardware configurations.

Improves startup times for applications that have roaming settings when User Experience Virtualization (UE-V) is turned on.

Addresses an issue in which a principal in a trusted MIT realm fails to obtain a Kerberos service ticket from Active Directory domain controllers (DC). This occurs on devices that installed Windows Updates that contain CVE-2020-17049 protections and configured PerfromTicketSignature to 1 or higher. These updates were released between November 10, 2020 and December 8, 2020. Ticket acquisition also fails with the error, “KRB_GENERIC_ERROR”, if callers submit a PAC-less Ticket Granting Ticket (TGT) as an evidence ticket without providing the USER_NO_AUTH_DATA_REQUIRED flag.

Addresses high memory and CPU utilization in Microsoft Defender for Endpoint.

Enhances data loss prevention and insider risk management solution functionalities in Microsoft 365 endpoints.

Addresses an issue that displays an error when you attempt to open an untrusted webpage using Microsoft Edge or open an untrusted Microsoft Office document. The error is, "WDAG Report - Container: Error: 0x80070003, Ext error: 0x00000001". This issue occurs after installing the .NET update KB4565627.

Addresses an issue that prevents wevtutil from parsing an XML file.

Addresses an issue that fails to report an error when the Elliptic Curve Digital Signature Algorithm (ECDSA) generates invalid keys of 163 bytes instead of 165 bytes.

Adds support for using the new Chromium-based Microsoft Edge as the assigned access single kiosk app. Now, you can also customize a breakout key sequence for single app kiosks. For more information, see Configure Microsoft Edge kiosk mode.

Addresses an issue with User Datagram Protocol (UDP) broadcast packets that are larger than the maximum transmission unit (MTU). Devices that receive these packets discard them because the checksum is not valid.

Addresses an issue in which the WinHTTP AutoProxy service does not comply with the value set for the maximum Time To Live (TTL) on the Proxy Auto-Configuration (PAC) file. This prevents the cached file from updating dynamically.

Displays the proper Envelope media type as a selectable output paper type for Universal Print queues.

Ends the display of a random paper size for a printer when it uses the Microsoft Internet Printing Protocol (IPP) Class Driver.

Enables Windows to retrieve updated printer capabilities to ensure that users have the proper set of selectable print options.

Updates support for hole punch and stapling locations for print jobs with long edge first paper feed direction on certain printers.

Addresses an issue that might cause the IKEEXT service to stop working intermittently.

Addresses an issue that might prevent a Non-Volatile Memory Express (NVMe) device from entering the proper power state.

Addresses an issue that might cause stop error 7E in nfssvr.sys on servers running the Network File System (NFS) service.

Addresses an issue that prevents the User Profile Service from detecting a slow or a fast link reliably.

Addresses an issue that causes contention for a metadata lock when using Work Folders.

Adds a new dfslogkey as described below:

Keypath: HKEY_LOCAL_MACHINE/SOFTWARE/MICROSOFT/dfslog.

The RootShareAcquireSuccessEvent field has the following possible values:

Default value = 1; enables the log.

Value other than 1; disables the log.
If this key does not exist, it will be created automatically. To take effect, any change to dfslog/RootShareAcquireSuccessEvent in the registry requires that you restart the DFSN service.

Updates the Open Mobile Alliance (OMA) Device Management (DM) sync protocol by adding a check-in reason for requests from the client to the server. The check-in reason will allow the mobile device management (MDM) service to make better decisions about sync sessions. With this change, the OMA-DM service must negotiate a protocol version of 4.0 with the Windows OMA-DM client.

Turns off token binding by default in Windows Internet (WinINet).

Addresses an issue with failover in an environment that only has IPv6 clusters. If the failover cluster has been running for more than 24 days, attempts to do a failover might not succeed or might be delayed.

There's also one other fix, which is exclusive to 20H2:

Improves the ability of the WinHTTP Web Proxy Auto-Discovery Service to ignore invalid Web Proxy Auto-Discovery Protocol (WPAD) URLs that the Dynamic Host Configuration Protocol (DHCP) server returns.

There are also two known issues to be aware of:

Symptoms	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.
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.

Symptoms

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.

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.

It's worth noting that Windows 10 version 21H1 is coming soon, and that's going to be an enablement package just like 20H2 was. That means that in a few months when 21H1 is out and version 1909 is no longer supported, all supported versions of Windows 10 will actually get the same updates.

As mentioned earlier, this update will arrive via Windows Update. If you choose not to take it, the fixes will be bundled into next month's Patch Tuesday update.