Description of Preview of Quality Rollup for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7 and 4.7.1 for Windows 8.1, RT 8.1 and Server 2012 R2 (KB 4073700)

Applies to: .NET Framework 4.7.1.NET Framework 4.7.NET Framework 4.6.2


This February 2018 update for Windows 8.1, Windows RT 8.1 and Windows Server 2012 R2 includes cumulative reliability improvements in .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, and 4.7.1. We recommend that you apply this update as part of your regular maintenance routines. Before you install this update, see the "Prerequisites" and "Restart requirement" sections.


  • All updates for Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 require update 2919355 to be installed. We recommend that you install update 2919355 on your Windows RT 8.1-based, Windows 8.1-based, or Windows Server 2012 R2-based computer so that you receive updates in the future.
  • 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.

Quality and reliability improvements

For .NET Framework 4.6, 4.6.1, 4.6.2, 4.7 and 4.7.1


  • Fixes an issue in which applications that make heavy use of System.Diagnostics.StackTrace or Exception.StackTrace might run slower on .NET Framework 4.7.1.
  • Fixes an issue in which CultureAwareComparer does not correctly serialize across versions.


  • Fixes an issue in which the AppContext switch Switch.System.Net.DontEnableSchSendAuxRecord does not correctly let the switch be enabled.
  • Fixes an issue that affects connection limits when HttpClient is used to send requests to loopback addresses. For more information about this issue, go to the following topic on the Microsoft website:


  • Fixes an issue in which deserialization is slow when big object lists are encountered. The fix makes the binary formatter faster.


  • Fixes an issue in which Dual GPU systems encounter visual artifacts when you run WPF applications in High Contrast.
  • Fixes an issue in a specific cases in which System.Windows.Controls.PrintDialog() throws an Arithmetic Overflow exception.
  • Fixes an issue in which WPF applications that are running on touch or stylus-enabled systems may crash or hang after some time without any touch activity.

1 Base Class Library (BCL)
2 Network Class Library (NCL)
3 Windows Communication Foundation (WCF)
4 Windows Presentation Foundation (WPF)

Additional information about this update

For more information about this update as it relates to Windows 8.1, Windows RT 8.1 and Windows Server 2012 R2, see the following article in the Microsoft Knowledge Base:

4074807 February 2018 Preview of the Quality Rollups for .NET Framework 3.5 SP1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, and 4.7.1 for Windows 8.1, RT 8.1 and Server 2012 R2 (KB 4074807)

How to get this update

Windows Update

This update is available through Windows Update. When you turn on automatic updating, this update will be downloaded and installed automatically. For more information about how to get security updates automatically, see Windows Update: FAQ.

Microsoft Update Catalog

To get the stand-alone package for this update, go to the Microsoft Update Catalog website.

Windows Software Update Services (WSUS)

On your WSUS server, follow these steps:

  1. Click Start, click Administrative Tools, and then click Microsoft Windows Server Update Services 3.0.
  2. Expand ComputerName, and then click Action.
  3. Click Import Updates.

    Note WSUS opens a browser window in which you may be prompted to install an ActiveX control. You must install the ActiveX control to continue.
  4. After the ActiveX control is installed, you will see the Microsoft Update Catalog screen. Enter 4074807 in the Search box, and then click Search.
  5. Locate the .NET Framework packages that match the operating systems, languages, and processors in your environment. Click Add to add them to your basket.
  6. After you select all the packages you require, click View Basket.
  7. To import the packages to your WSUS server, click Import.
  8. To return to WSUS, click Close after the packages are imported.

The updates are now available for installation through WSUS.


To apply this update, you must have .NET Framework 4.6, 4.6.1, 4.6.2, 4.7 or 4.7.1 installed.

Restart requirement

You must restart the computer after you apply this update if any affected files are being used. We recommend that you exit all .NET Framework-based applications before you apply this update.

Update replacement information

This update replaces previously released updates 4042078 and 4057272.

File information