Revised 11/16/23: to correct stated availablility on Windows Update for Business devices.
IMPORTANT
This update was originally released in the Security and Quality Rollup that’s dated September 26, 2023. This update is included in the Security and Quality Rollup that’s dated October 10, 2023. There is no change to this update with this release on October 10, 2023. If you have previously installed this update no action is needed.
Release Date:
September 26, 2023Version:
.NET Framework 3.5 and 4.8.1The September 26, 2023 update for Windows 11, 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
ASP.NET |
- Addresses an issue with "System.ArgumentException: Illegal characters in path" in some ASP.Net MVC requests. |
SqlClient |
- Addresses an issue with SQL event source telemetry. |
Additional information about this update
The following articles contain additional information about this update as it relates to individual product versions.
-
5031225 Description of the Cumulative Update for .NET Framework 3.5, 4.8 and 4.8.1 for Windows 11 for x64 (KB5031225)
Known issues in this update
Microsoft is not currently aware of any issues in this update.
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 |
Yes |
None. This update will be downloaded and installed automatically from Windows Update. |
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 11, 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
-
Help for installing updates: Windows Update FAQ
-
Protect yourself online and at home: Windows Security support
-
Local support according to your country: International Support