Besides the latest optional update KB5012643 for Windows 11 (21H2), which is designed to safely fix screen flickering without network drivers, some services such as Explorer or the Start menu actually cause more trouble than good. The company suggests removing it and says it’s already working on a fix.

It turned out that the update for Windows 11 also affected some programs, impairing their performance. In particular, problems occur with applications that use the .NET Framework 3.5. While Microsoft has not specifically disclosed all the potential problems caused by the update, it does not specifically allow you to run applications that use this framework. The issue did not affect all programs using the NET Framework 3.5, only those using the Windows Communication Foundation (WCF) and Windows Workflow (WWF) components.

One solution is to uninstall the KB5012463 update. If for some reason this is not possible, another solution is to restart the .NET Framework 3.5 and WCF in the list of components and services of the Windows operating system. To do this, open a command prompt and enter the following commands:

• dism / online / enable feature / feature name: netfx3 / all
• dism / online / enable feature / feature name: WCF-HTTP-Activation
• dism / online / enable feature / feature name: WCF-NonHTTP-Activation

Microsoft is working on a more reliable solution to the problem and will provide it with a new operating system update. The company did not specify when that would happen. Source