December 11, 2018—KB4471321 (OS Build 14393.2665)

Applies to: Windows 10, version 1607Windows Server 2016

Improvements and fixes


This update includes quality improvements. No new operating system features are being introduced in this update. Key changes include:

  • Addresses an issue that may prevent the use of the Seek Bar in Windows Media Player when playing specific files. This issue does not affect normal playback.
  • Addresses an issue that may cause the entire system to become unresponsive when using features related to end-user-defined characters (EUDC).
  • Security updates to Internet Explorer, Microsoft Scripting Engine, Windows App Platform and Frameworks, Microsoft Graphics Component, Windows Graphics, Microsoft Edge, Windows Kernel, Windows Wireless Networking, and Windows Authentication.

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 you install the August Preview of Quality Rollup or September 11, 2018 .NET Framework update, instantiation of SqlConnection can throw an exception. For more information about this issue, see the following article in the Microsoft Knowledge Base:

4470809 SqlConnection instantiation exception on .NET 4.6 and later after August-September 2018 .NET Framework updates.

This issue is resolved in KB4480977.

For hosts managed by System Center Virtual Machine Manager (SCVMM), SCVMM cannot enumerate and manage logical switches deployed on the host after installing the update.

Additionally, if you do not follow the best practices, a stop error may occur in vfpext.sys on the hosts.
  1. Run mofcomp on the following mof files on the affected host:
    • Scvmmswitchportsettings.mof
    • VMMDHCPSvr.mof
  2. Follow the best practices while patching to avoid a stop error in vfpext.sys in an SDN v2 environment (NC managed hosts).
After installing this update on Windows Server 2016, instant search in Microsoft Outlook clients fail with the error, "Outlook cannot perform the search".

This issue is resolved in KB4487026.

After installing KB4467684, the cluster service may fail to start with the error “2245 (NERR_PasswordTooShort)” if the Group Policy “Minimum Password Length” is configured with greater than 14 characters.

Set the domain default "Minimum Password Length" policy to less than or equal to 14 characters.

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

After installing KB4467691, Windows may fail to start on certain Lenovo and Fujitsu laptops that have less than 8 GB of RAM.

Restart the affected machine using the Unified Extensible Firmware Interface (UEFI). Disable Secure Boot and then restart.

If BitLocker is enabled on your machine, you may have to go through BitLocker recovery after Secure Boot has been disabled.

Lenovo and Fujitsu are aware of this issue. Please contact your OEM to ask if there is a firmware update available for your device.

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 more information, see Servicing stack updates.

If you are using Windows Update, the latest SSU (KB4465659) will be offered to you automatically. To get the stand-alone package for the latest SSU, go to the Microsoft Update Catalog.

Install this update

This update will be downloaded and installed automatically from Windows Update. To get the stand-alone 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 4471321.