November 13, 2019
.NET Framework 3.5 and 4.8
This update for Windows 10 Version 1903 and Windows Server 1903 RTM and Windows 10, version 1909 and Windows Server, version 1909 includes a fix to an issue introduced in the October 24th Cumulative update. See the Quality and reliability improvements section for more details. Before you install this update, see the Prerequisites and Restart requirement sections.
Quality and reliability improvements
Address an issue where ClickOnce applications and applications creating the default AppDomain with a restricted permission set may observe application launch or application runtime failures, or unexpected behaviors. The observable issue was the System.AppDomainSetup.TargetFrameworkName is null, leading to any quirks enabling reverting back to .NET Framework 4.0 behaviors.
1 Common Language Runtime (CLR)
Known Issues in this update
There are no known issues with this update, however, this update resolves a previous known issue. This patch includes improvements to resolve a known issue discussed in KB4519573 that occurs after applying the October Preview of Quality Rollup for .NET Framework 4.8. To resolve this issue, install update for .NET Framework 4.8 for Windows 10, version 1903 and Windows Server 1903 RTM and Windows 10, version 1909 and Windows Server, version 1909 KB4533002.