Release Date:October 11, 2022

Version: .NET Framework 3.5 and 4.8.1

IMPORTANT

This update was originally released in the Security and Quality Rollup that’s dated September 20, 2022.  This update is included in the Security and Quality Rollup that’s dated October 11, 2022.  There is no change to this update with this release on October 11, 2022.  If you have previously installed this update no action is needed.

The September 20, 2022 update for Windows 10, version 20H2, Windows 10 Version 21H1, and Windows 10 Version 21H2 includes cumulative reliability improvements in .NET Framework 3.5 and 4.8.1. 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.

Summary

Security Improvements

There are no new security improvements in this release. This update is cumulative and contains all previously released security improvements.

Quality and Reliability Improvements

WPF1

- Addresses an issue of WPF apps not working with "Text Cursor Indicator" enabled when using RichTextBox.

- Addresses an issue to allow users to adjust column width for Datagrid and Gridview controls using keybord

- Addresses issues arising in TreeView (or ListBox/DataGrid with grouping enabled) when changing the underlying collection(s) while also collapsing or expanding TreeView nodes. Scrolling actions, especially "short" actions like LineUp or MouseWheelUp, can result in poor outcomes: hangs, crashes, unexpected scrolling, gaps in the display, etc.

- Addresses an issue where opening a tooltip causes an ArgumentOutOfRangeException, when the app has changed the floating point control word.

- Addresses an issue where invoking a synchronization Wait on the UI thread can lead to a render-thread failure, due to unexpected re-entrancy.

- Addresses an issue where DWM failures can cause WPF's render thread to fail. An app can opt-in to the behavior of ignoring all DwmFlush errors by setting a regkey in HKCU\Software\Microsoft\Avalon.Graphics\IgnoreDwmFlushErrors or HKLM\Software\Microsoft\Avalon.Graphics\IgnoreDwmFlushErrors whose name is the full path to the .exe that wants to opt-in, and whose DWORD value is 1.

Winforms

- Improved keyboard navigation in ToolStrip ComboBox and TextBox items.

- Improved color contrast in System.Windows.Forms.DataGridView control's link cells.

- Enabled Narrator to focus on System.Windows.Forms.DataGridView control even if it's empty.

Workflow

- Addresses an issue when users interact with the Workflow Designer, they might encounter incorrectly disabled context menu items when right clicking on a variable in the component variables list.

.NET Runtime

- Improved reliability of managed debugging on arm64.

- Adjusted GC Heap Hard Limit configuration, as well as processor interpretation for .NET Framework container scenarios.

- Improved security of code identified by internal compliance scans.

- Improved deterministic output capability in ilasm.exe.

Networking

- Addresses an issue when Ssl negotiation can hang indefinitely when client certificates are used when TLS 1.3 is negotiated. Before the change renegotiation (PostHandshakeAuthentiction) would fail and SslStream or HttpWebRequest would observe timeout. Possible workaround is disabling TLS 1.3 either via Switch.System.Net.DontEnableTls13 AppContext or via OS registry.

1Windows Presentation Foundation (WPF)

Additional information about this update

The following articles contain additional information about this update as it relates to individual product versions.

  • 5018543 Description of the Cumulative Update for .NET Framework 3.5, 4.8 and 4.8.1 for Windows 10 Version 20H2 (KB5018543)

  • 5018544 Description of the Cumulative Update for .NET Framework 3.5, 4.8 and 4.8.1 for Windows 10 Version 21H1 (KB5018544)

  • 5018545 Description of the Cumulative Update for .NET Framework 3.5, 4.8 and 4.8.1 for Windows 10 Version 21H2 (KB5018545)

Known issues in this update

The September 2022 preview release is listed in Windows Server Update Services IT Administrators who utilize Windows Server Update Services (WSUS) might notice that this KB is listed among the updates available from WSUS. This listing is an error. Preview updates are generally only available for manual importing via to the Microsoft Update Catalog.

Home users of Windows are unlikely to experience this issue. WSUS is commonly utilized by technology administrators to deploy Microsoft product updates in managed environments.

Please note: In environments where WSUS is configured to auto-approve updates and also auto-decline superseded content, the .NET Framework September 2022 Security and Quality Rollup Update may subsequently be auto-decline and auto-expired from the client view. If this occurs, see the guidance for reinstating declined updates. Then, run an update synchronization within Microsoft Endpoint Configuration Manager, or update management environments. Environments configured to only take security updates should not reflect these symptoms.

Resolution: This issue is now resolved.

How to get this update

Install this update

Release Channel

Available

Next Step

Windows Update and Microsoft Update

Yes

None. This update will be downloaded and installed automatically from Windows Update.

Windows Update for Business

No

None. These changes will be included in the next security update to this channel. For more information about Windows Update for Business go to the Windows Update for Business website.

Microsoft Update Catalog

Yes

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

Windows Server Update Services (WSUS)

Yes

This update will automatically sync with WSUS if you configure Products and Classifications as follows:

Product: Windows 10, version 20H2, Windows 10 Version 21H1, and Windows 10 Version 21H2

Classification: Updates

File information

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

Prerequisites

To apply this update, you must have .NET Framework 3.5 or 4.8.1 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.

How to obtain help and support for this update

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