The list of issues surrounding the Windows 11 KB5012643 update is growing. Fortunately, it is offered as an option. Clearly its download and installation require manual intervention on the part of the user.
Since it was put online through the Windows Update service, it has caused several failures. One of the most problematic has affected Safe Mode. We’re also having trouble with popular Windows 11 apps like File Explorer.
Installing KB5012643 allows Windows 11 to upgrade to version 22000.652. If its content is interesting, it is unfortunately the source of several more or less annoying bugs. Microsoft is the originator of workarounds. One of them is simply to uninstall KB5012643.
Windows 11 et KB5012643
One of the latest issues discovered is with Windows 1 applications. Microsoft explains that some .NET Framework 3.5 software may crash after installing KB5012643.
Windows 11, update KB5012643 arrives, what’s new?
We don’t have an exhaustive list of all potential issues, but one is preventing some apps from working. The bug does not affect all .NET Framework 3.5 applications but seems to affect only those using optional .NET Framework 3.5 components such as Windows Communication Foundation (WCF) et Windows Workflow (WWF).
One of the workarounds, until a fix is released, is to uninstall KB5012463 from Windows Update. If this is not possible, another approach is to re-enable .NET Framework 3.5 and WCF from Windows Features. You can also do this through a command prompt by running the following commands
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 since KB5012643 only targets Windows 11 21H2.