This update reportedly causes a crash for some older .NET applications:
Microsoft warns users: Uninstall Windows 11 KB5012643 if it crashes your apps
I ran into this issue a couple days ago and took a dive to see what the cause might be. I noticed that there's a missing entry for
System.Runtime.Serialization, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 in the older GAC. This is the location at %WINDIR%\assembly and
not %WINDIR%\Microsoft.NET\assembly. You can verify this with gacutil.exe (as long as it's the older version that searches the appropriate GAC). I used an old Visual Studio 2008 Developer command prompt to check.
I was able to fix the issue simply by checking and unchecking a box in the "Turn Windows features on or off" dialog, which can be found from the start menu. More specifically, the ".NET Framework 3.5 (includes .NET 2.0 and 3.0)" item... Uncheck that, restart windows, open the dialog again, check the box and opt to reinstall all of the files from Windows Update. I restarted one last time after this to ensure all pending operations were completed successfully.
.NET assemblies are lazily loaded at runtime, unless preloaded for any reason. The crash will occur the first time System.Runtime.Serialization is required.
Following are the highlights for
KB5013643 (OS Build 22000.652) for Windows 11:
There's a typo here however, it's not "KB501
3646" it's "KB501
2643".
