Hyper-V guest may freeze when it is running failover cluster service together with shared VHDX in Windows Server 2012 R2

This article describes an issue that occurs when a Hyper-V guest is running failover cluster service together with a shared virtual hard disk (VHDX) in Windows Server 2012 R2. Before you install this update, see the Prerequisites section.
When this issue occurs, the Hyper-V guest is still registered as running in both Hyper-V manager and Failover Cluster manager. Therefore, the service in the cluster role doesn't failover to the passive guest cluster node correctly.
How to get this update
Important If you install a language pack after you install this update, you must reinstall this update. Therefore, we recommend that you install any language packs that you need before you install this update. For more information, see Add language packs to Windows.

Method 1: Windows Update

This update is provided as a Recommended update on Windows Update. For more information on how to run Windows Update, see How to get an update through Windows Update.

Method 2: Microsoft Download Center

The following files are available for download from the Microsoft Download Center:
Operating systemUpdate
All supported x64-based versions of Windows 8.1 DownloadDownload the package now.
All supported x64-based versions of Windows Server 2012 R2DownloadDownload the package now.
For more information about how to download Microsoft support files, select the following article number to view the article in the Microsoft Knowledge Base:
119591 How to obtain Microsoft support files from online services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.
Update detail information


To install this update, you should first install April 2014, update rollup for Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 (2919355) in Windows Server 2012 R2.

Registry information

To apply this update, you don't have to make any changes to the registry.

Restart requirement

You may have to restart the computer after you apply this update.

Update replacement information

This update doesn't replace a previously released update.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Learn about the terminology that Microsoft uses to describe software updates.
File Information
The English (United States) version of this software update installs files that have the attributes that are listed in the following tables.

Windows 8.1 and Windows Server 2012 R2

  • The files that apply to a specific product, milestone (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table:
    VersionProductMilestoneService branch
    6.3.960 0.18 xxxWindows 8.1 and Windows Server 2012 R2RTMGDR
  • GDR service branches contain only those fixes that are widely released to address widespread, critical issues. LDR service branches contain hotfixes in addition to widely released fixes.
  • The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed in the "Additional file information" section. MUM, MANIFEST, and the associated security catalog (.cat) files, are very important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.
x64 Windows 8.1 and Windows Server 2012 R2
File nameFile versionFile sizeDateTimePlatform

Additional file information

x64 Windows 8.1 and Windows Server 2012 R2
File propertyValue
File nameAmd64_075f3451b68b4847ba1649f5b825ca3f_31bf3856ad364e35_6.3.9600.18229_none_432680fa4b2bcc7d.manifest
File versionNot applicable
File size703
Date (UTC)05-Feb-2016
Time (UTC)19:02
PlatformNot applicable
File nameAmd64_microsoft-hyper-v-pvhd-parser_31bf3856ad364e35_6.3.9600.18229_none_7a7e6ee5ae0f078a.manifest
File versionNot applicable
File size3,908
Date (UTC)05-Feb-2016
Time (UTC)15:47
PlatformNot applicable
File nameUpdate.mum
File versionNot applicable
File size2,272
Date (UTC)05-Feb-2016
Time (UTC)19:02
PlatformNot applicable

Article ID: 3139896 - Last Review: 04/12/2016 20:38:00 - Revision: 2.0

Windows Server 2012 R2 Datacenter, Windows Server 2012 R2 Standard, Windows Server 2012 R2 Essentials, Windows Server 2012 R2 Foundation, Windows 8.1 Enterprise, Windows 8.1 Pro, Windows 8.1

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