The list of issues related to the Windows 11 KB5012643 update is growing. Fortunately, it is offered as an option. Obviously its download and installation requires manual intervention on the part of the user.

Since it was put online through the Windows Update service, it has caused many failures. One of the most problematic has affected Safe Mode. We are also bothered by popular Windows 11 apps like File Explorer.

Installing KB5012643 allows upgrading Windows 11 to version 22000.652. If its content is interesting, it is unfortunately the source of many more or less annoying bugs. Microsoft is the originator of the workaround. One of them is simply to uninstall KB5012643.

Windows 11 and KB5012643

One of the latest issues discovered is with Windows 1 applications. Microsoft states that some .NET Framework 3.5 software may crash after KB5012643 is installed.

Windows 11, Update KB5012643 Arrived, What’s New?

We don’t have a complete list of all possible problems, but some are preventing apps from working. The bug does not affect all .NET Framework 3.5 applications but appears to only affect those using optional .NET Framework 3.5 components such as woowindows VsCommunications Ffoundation (WCF) and woowindows wooorkflowwoo (WWF).

One solution, until a solution is released, is to uninstall KB5012463 from Windows Update. If this is not possible, another way is to re-enable the .NET Framework 3.5 and WCF from Windows Features. You can also do this through Command Prompt by running the following command:

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

These solutions are only temporary knowing that Microsoft is working on the issue. However, we do not have an exact timetable. These failures do not affect Windows 10 and Windows Server as KB5012643 only targets Windows 11 21H2.