May 14, 2019—KB4494441 (OS Build 17763.503)

Applies to: Windows 10, version 1809Windows Server 2019, all versions

Improvements and fixes


This update includes quality improvements.  Key changes include:

  • Enables “Retpoline” by default if Spectre Variant 2 (CVE-2017-5715) is enabled. Make sure previous OS protections against the Spectre Variant 2 vulnerability are enabled using the registry settings described in the Windows Client and Windows Server articles. (These registry settings are enabled by default for Windows Client OS editions, but disabled by default for Windows Server OS editions). For more information about “Retpoline”, see Mitigating Spectre variant 2 with Retpoline on Windows.
  • Provides protections against a new subclass of speculative execution side-channel vulnerabilities, known as Microarchitectural Data Sampling, for 64-Bit (x64) versions of Windows (CVE-2019-11091, CVE-2018-12126, CVE-2018-12127, CVE-2018-12130). Use the registry settings as described in the Windows Client and Windows Server articles. (These registry settings are enabled by default for Windows Client OS editions and Windows Server OS editions).
  • Adds "gov.uk" to the HTTP Strict Transport Security Top Level Domains (HSTS TLD) for Internet Explorer and Microsoft Edge.
  • Addresses an issue that may cause “Error 1309” while installing or uninstalling certain types of .msi and .msp files on a virtual drive.
  • Addresses an issue that prevents the Microsoft Visual Studio Simulator from starting.
  • Addresses an issue that may cause zone transfers between primary and secondary DNS servers over the Transmission Control Protocol (TCP) to fail.
  • Addresses an issue that causes Simple Network Management Protocol (SNMP) Management Information Base registration to fail when the Windows Management Instrumentation (WMI) provider uses the Windows tool SMI2SMIR.exe.
  • Addresses an issue that may cause the text, layout, or cell size to become narrower or wider than expected in Microsoft Excel when using the MS UI Gothic or MS PGothic fonts. 
  • Security updates to Microsoft Edge, Internet Explorer, Microsoft Scripting Engine, Windows App Platform and Frameworks, Windows Graphics, Windows Storage and Filesystems, Windows Cryptography, the Microsoft JET Database Engine, Windows Kernel, Windows Virtualization, and Windows Server .

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 Security Update Guide.

Known issues in this update


Symptom Workaround
After installing this update, there may be issues using the Preboot Execution Environment (PXE) to start a device from a Windows Deployment Services (WDS) server configured to use Variable Window Extension. This may cause the connection to the WDS server to terminate prematurely while downloading the image. This issue does not affect clients or devices that are not using Variable Window Extension.

This issue is resolved in KB4503327.

Certain operations, such as rename, that you perform on files or folders that are on a Cluster Shared Volume (CSV) may fail with the error, “STATUS_BAD_IMPERSONATION_LEVEL (0xC00000A5)”. This occurs when you perform the operation on a CSV owner node from a process that doesn’t have administrator privilege.

Do one of the following:

  • Perform the operation from a process that has administrator privilege.
  • Perform the operation from a node that doesn’t have CSV ownership.
Microsoft is working on a resolution and will provide an update in an upcoming release.
When attempting to print from Microsoft Edge or other Universal Windows Platform (UWP) applications, you may receive the error, "Your printer has experienced an unexpected configuration problem. 0x80070007e."

You can use another browser, such as Internet Explorer to print your documents.

Microsoft is working on a resolution and will provide an update in an upcoming release.

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:

  1. Go to the Settings app > Recovery.
  2. Select Get Started under the Reset this PC recovery option.
  3. Select Keep my Files.

Microsoft is working on a resolution and will provide an update in an upcoming release.

Some customers report that KB4494441 installed twice on their device. 

In certain situations, installing an update requires multiple download and restart steps. If two intermediate steps of the installation complete successfully, the View your Update history page will report that installation completed successfully twice.

No action is required on your part. The update installation may take longer and may require more than one restart, but will install successfully after all intermediate installation steps have completed.

We are working on improving this update experience to ensure the Update history correctly reflects the installation of the latest cumulative update (LCU).

After installing the May 14, 2019 update, some gov.uk websites that don’t support HTTP Strict Transport Security (HSTS) may not be accessible through Internet Explorer 11 or Microsoft Edge. This issue is resolved in KB4505056.

How to get this update


Before installing this update

Prerequisite: The servicing stack update (SSU) (KB4499728) must be installed before installing the latest cumulative update (LCU). The LCU will not be reported as applicable until the SSU is installed. For more information, see Servicing stack updates.

If you are using Windows Update, the latest SSU (KB4499728) 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

This update will be downloaded and installed automatically from Windows Update. To get the standalone package for this update, go to the Microsoft Update Catalog website.

File information

For a list of the files that are provided in this update, download the file information for cumulative update 4494441