November 19, 2020-KB4586878 Cumulative Update Preview for .NET Framework 3.5 and 4.8 for Windows 10, version 1903, Windows Server, version 1903, Windows 10, version 1909, and Windows Server, version 1909

Applies to: .NET

The November 19, 2020 update for Windows 10, version 1903, Windows Server, version 1903, Windows 10, version 1909, and Windows Server, version 1909 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

- Addressed an issue with a FailFast crash arising in apps with two threads that both load application resources.

Runtime

- Improved the clean-up process for X509Certificate2 certificates


1 Windows Presentation Foundation (WPF)

How to obtain and install the 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) No

You can import this update into WSUS manually. See the Microsoft Update Catalog for instructions.

 

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