Description of Preview of Quality Rollup for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, and 4.7.2 for Windows 8.1, RT 8.1, and Server 2012 R2 (KB 4457015)

Applies to: .NET Framework 4.7.2.NET Framework 4.7.1.NET Framework 4.7

Notice


This update is included in the Security and Quality Rollup that's dated October 9, 2018. This update was previously released as part of the Preview of Quality Rollup on September 18, 2018.

Introduction


This September 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, 4.7.1, and 4.7.2. 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.

Important

  • All updates for Windows 8.1, Windows RT 8.1, and Windows Server 2012 R2 require that update KB 2919355 is installed. We recommend that you install update KB 2919355 on your Windows 8.1-based, Windows RT 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


CLR1

  • Fixes an issue in which parsing Japanese dates that have a year number that exceeds the number of years in that date era succeeds instead of throwing an error.
  • Fixes an issue in which, when asynchronously reading a process output, an IndexOutOfRangeException message is thrown when less than a character's worth of bytes is read at the beginning of a line.
  • Fixes an issue in the JIT compiler for a rare case of structure field assignments as described on GitHub.
  • Fixes the DateTime.Now and DateTime.Utc properties so that they are always synchronized with the system time. DateTime and DateTimeOffset operations continue to work as they used to work.
  • Conditionally improves Spin-waits in several synchronization primitives to run better on Intel Skylake and more recent microarchitectures. To enable these improvements, set the new configuration variable COMPlus_Thread_NormalizeSpinWait to 1.
  • Fixes JIT optimization which resulted in removal of interlocked Compare Exchange operations.

WPF2

  • Fixes an issue that occurs under certain circumstances in which WPF applications that use the spell checker together with custom dictionaries can throw unexpected exceptions and crash.

1 Common Language Runtime (CLR)
2 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 articles in the Microsoft Knowledge Base:

4459924 Security and Quality Rollup updates for .NET Framework 3.5, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, and 4.7.2 for Windows 8.1, RT 8.1, and Server 2012 R2 (KB 4459924)

4458613 September 2018 Preview of the Quality Rollups for .NET Framework 3.5, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, and 4.7.2 for Windows 8.1, RT 8.1, and Server 2012 R2 (KB 4458613)

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. Select Start, select Administrative Tools, and then select Microsoft Windows Server Update Services 3.0.
  2. Expand ComputerName, and then select Action.
  3. Select Import Updates.
  4. WSUS opens a browser window in which you may be prompted to install an ActiveX control. Install the ActiveX control to continue.
  5. After the ActiveX control is installed, you see the Microsoft Update Catalog screen. Type 4459924 in the Search box, and then select Search.
  6. Locate the .NET Framework packages that match the operating systems, languages, and processors in your environment. Select Add to add them to your basket.
  7. After you select all the packages that you need, select View Basket.
  8. To import the packages to your WSUS server, select Import.
  9. After the packages are imported, select Close to return to WSUS.

The updates are now available for installation through WSUS.

Prerequisites

To apply this update, you must have .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, or 4.7.2 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 update KB 4346082.

File information

The English (United States) version of this update installs files that have the attributes that are listed in the following tables. The dates and times for these files are listed in Coordinated Universal Time (UTC). The dates and times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and times may change when you perform certain operations on the files.

How to obtain help and support for this update