Applies To
Windows 8.1 Windows Server 2012 R2 Windows Embedded 8.1 Industry Enterprise Windows Embedded 8.1 Industry Pro

Release Date:

13/04/2021

Version:

Security-only update

Important:Ā Windows 8.1 and Windows Server 2012 R2 haveĀ reached the end of mainstream support and areĀ now in extended support.Ā Starting in July 2020, there will no longer be optional, non-security releases (known asĀ "C"Ā releases) for this operating system. Operating systems in extended support haveĀ onlyĀ cumulative monthly security updates (known as the "B" or Update Tuesday release). For information about the various types of Windows updates, such as critical, security, driver, service packs, and so on, please see the followingĀ article.Ā To view other notes andĀ messages, see the Windows 8.1 and Windows Server 2012 R2 updateĀ historyĀ home page.

Improvements and fixes

This security update includes quality improvements. Key changes include:

  • Addresses a time zone change for Volgograd, Russia from UTC+4 to UTC+3 Moscow Standard Time (MSK).

  • Addresses a time zone change for The Republic of South Sudan from UTC+3 to UTC+2 Juba. For more information about this change, see KB 4601275.

  • Security updates to Windows Input and Composition, Windows Fundamentals, Windows Hybrid Cloud Networking, Windows Kernel, and Windows Media.

For more information about the resolved security vulnerabilities, please refer to the newĀ Security Update GuideĀ website.

Known issues in this update

Symptom

Workaround

Certain operations, such asĀ rename, that you perform on files or folders that are on a Cluster Shared Volume (CSV) may fail with the error, ā€œSTATUS_BAD_IMPERSONATION_LEVEL (0xC00000A5)ā€. 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.

How to get this update

Before installing this update

We strongly recommend thatĀ you install the latest servicing stack update (SSU) for your operating system before you installĀ the latest Rollup. SSUs improve the reliability of the update process to mitigate potential issues while installing the Rollup and applying Microsoft security fixes.Ā For general information about SSUs,Ā seeĀ Servicing stack updatesĀ andĀ Servicing Stack Updates (SSU): Frequently Asked Questions.

If you useĀ Windows Update, the latest SSUĀ (KB5001403) will be offered to you automatically.Ā To get the standalone package for the latestĀ SSU, search for it in theĀ Microsoft Update Catalog.Ā 

REMINDERĀ If you are using Security-only updates, you will also need to install all previous Security-only updates and the latest cumulative update for Internet Explorer (KB5000800).Ā 

Install this update

Release Channel

Available

Next Step

Windows Update and Microsoft Update

No

See the other options below.

Microsoft Update Catalog

Yes

To get the standalone package for this update, go to theĀ Microsoft Update CatalogĀ website.

Windows Server Update Services (WSUS)

Yes

This update will automatically syncĀ with WSUS if you configureĀ Products and ClassificationsĀ as follows:

Product: Windows 8.1, Windows Server 2012 R2,Ā Windows Embedded 8.1 Industry Enterprise, Windows Embedded 8.1 Industry Pro

Classification: Security Updates

File information

For a list of the files that are provided in this update, download theĀ file information for update 5001393.

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