August 10, 2021
.NET Framework 3.5 and 4.7.2
The August 10, 2021 update for Windows 10, version 1809 and Windows Server, version 2019 includes cumulative reliability improvements in .NET Framework 3.5 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.
There are no new security improvements in this release. This update is cumulative and contains all previously released security improvements.
Quality and reliability improvements
- In scenarios with both high numbers of assemblies and high numbers of GC heaps, Server GC can encounter serious lock contention during generation 2 GCs. A config switch has been introduced as a workaround. It can either be enabled from a .config file:
1 Common Language Runtime (CLR)
Additional information about this update
The following articles contain additional information about this update as it relates to individual product versions.
5004870 Description of the Cumulative Update for .NET Framework 3.5, 4.7.2 and 4.8 for Windows 10, version 1809 and Windows Server, version 2019 (KB5004870)
How to get this update
Install this update
Windows Update and Microsoft Update
To download and install this update, go to Settings > Update & Security > Windows Update, and then select Check for updates.
Microsoft Update Catalog
To get the standalone package for this update, go to the Microsoft Update Catalog website.
Windows Server Update Services (WSUS)
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
For a list of the files that are provided in this update, download the file information for cumulative update.
To apply this update, you must have .NET Framework 3.5 or 4.7.2 installed.
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
Known issues in this update
Microsoft is not currently aware of any issues in this update.