Preview of Quality Rollup for .NET Framework 4.8 for Windows Server 2012 (KB4537481)

Applies to: .NET Framework

The February 25, 2020 update for Windows Server 2012 includes cumulative reliability improvements in .NET 4.8. 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.

Quality and reliability improvements


CLR1

- Addresses an issue with rare crashes or deadlocks that could occur if a GC occurs while another thread is running NGen'ed code which makes the initial call into a static method within the same module where one or more parameter types involve type-forwarded value types.

- Addresses rare crashes that could occur if Server GC is enabled and a GC occurs while another thread is running NGen'ed code which is making the initial call into NGen'ed code in a 2nd module where one or more parameter types involve valuetypes defined in a 3rd module.

- Addresses an issue with a crash that could occur in some configurations involving either hot-added CPUs or multi-group machines where per-group CPU count is not consistent across all groups.

- Addresses an issue with a rare crash that can occur during the first call that native code makes into the managed portion of a mixed-mode DLL.

Workflow

- Addresses an accessibility issue where text inside a Windows Workflow Foundation Visual Basic Editor would use the wrong colors in high contrast themes.

Winforms

- Addresses an issue with interaction between WPF user control and hosting WinForms app when processing keyboard input.

- Addresses an issue getting accessible objects for PropertyGridView ComboBox property items - adding the verification for item existence and validity.

- Addresses an issue with WinForms ComboBox control reinitialization in AD FS MMC UI.

WCF2

- Addresses an issue when using the WCFNetTcp binding. If a client stops responding during the connection handshake, sometimes a service will use the binding receive timeout instead of the open timeout. This update ensures that the correct open timeout is used during the entire handshake.


1 Common Language Runtime (CLR)
2 Windows Communication Foundation (WCF)

Additional information about this update


The following articles contain additional information about this update as it relates to individual product versions.
  • 4538157 Description of the Preview of Quality Rollup for .NET Framework 3.5, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows Server 2012 (KB4538157)

How to obtain and install the update


Method 1: Windows Update

This update is available through Windows Update. Go to Settings > Update and Security > Windows Update, and then select Check for updates. For more information about how to get preview updates, see Windows Update: FAQ.

Method 2: Microsoft Update Catalog

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

Method 3: 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. You must install the ActiveX control to continue.
  5. After the ActiveX control is installed, you see the Microsoft Update Catalog screen. Type 4538157 into 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 require, 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 4.8 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 4535673.

File information


The English (United States) version of this software update installs files that have the attributes that are listed in the following tables.



Additional file information

How to obtain help and support for this update