KB5012643 is causing issues with some apps in Windows 11, but there's a workaround

Microsoft's latest Windows 11 optional update 22000.652 (KB5012643) has been causing more issues than it would like. It resulted in screen flickering in Safe Mode and some problems with File Explorer, with Microsoft then posting a workaround that involved uninstalling the update. Now, a new issue associated with this optional build is plaguing some Windows 11 apps, but the company is working on a fix.

As spotted by BetaNews, Microsoft has updated its Windows 11 known issues webpage to add that some .NET Framework 3.5 apps might suffer problems after installing KB5012643. Although the company hasn't highlighted all the potential problems, one includes apps not opening at all. It is important to note that this does not affect all .NET Framework 3.5 apps, it has only noticed this happening with those that are using optional .NET Framework 3.5 components such as Windows Communication Foundation (WCF) and Windows Workflow (WWF) components.

The workaround, once again, is to first try uninstalling KB5012463 from Windows Update. If this is not possible, another mitigation involves re-enabling .NET Framework 3.5 and WCF from Windows Features. You can do the same by running the following commands in Command Prompt:

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

It is important to note that both of these processes are only temporary workarounds, Microsoft is working on a more solid resolution for an "upcoming release" but hasn't defined a concrete timeline. Lastly, those on Windows 10 and Windows Server need not worry as this optional update is only available for Windows 11 version 21H2.

Source: Microsoft via BetaNews

KB5012643 is causing issues with some apps in Windows 11, but there's a workaround