June 8, 2021-KB5003254 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10, version 2004, Windows Server, version 2004, Windows 10, version 20H2, Windows Server, version 20H2 and Windows 10 Version 21H1
Release Date:
June 8, 2021Version:
.NET Framework 3.5 and 4.8The June 8, 2021 update for Windows 10, version 2004, Windows Server, version 2004, Windows 10, version 20H2, Windows Server, version 20H2, and Windows 10 Version 21H1 includes cumulative reliability improvements in .NET Framework 3.5 and 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
WPF1 |
- Addresses an issue when rapid typing using an IME can crash via FailFast. - Addresses an issue where Thaana characters displayed in left-to-right order. - Addresses a crash when WebBrowser receives a completion event for a navigation it tried to cancel. |
CLR2 |
- Addresses a performance issue caused by incorrect configuration in the GC. - Addresses an issue where a background GC could pause the runtime for a long period of time if a large managed heap is filled with long lived objects with a deep chain of references. - Addresses an issue where crashes could occur if security stackwalks were generated during ThreadAbortException handling. |
NCL3 |
- .Net Framework 4.8 will now allow to negotiate TLS 1.3 if underlying OS supports it. |
1 Windows Presentation Foundation (WPF)
2 Common Language Runtime (CLR) 3 Network Class Library (NCL)How to get this update
Install this update
Release Channel |
Available |
Next Step |
Windows Update and Microsoft Update |
Yes |
To download and install this update, go to Settings > Update & Security > Windows Update, and then select Check for updates. |
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 2004, Windows Server, version 2004, Windows 10, version 20H2, and Windows Server, version 20H2, and Windows Version 21H1 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 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
Known issues in this update
Microsoft is not currently aware of any issues in this update.