September security patch broke Linux WSL subsystem in Windows 10. Microsoft is working on a fix
Microsoft released a regular security update for its products this week as part of the Patch Tuesday program. Unfortunately, the KB4571756 package not only fixes old problems but also brings new ones. Some users noticed that after installing the security patch, the Linux subsystem of the Windows Subsystem for Linux stopped starting.
Judging by user reports, KB4571756 causes other minor problems, and in some cases, the update does not install correctly. As for the problem with the Linux subsystem, when trying to start it, some users get an error stating that “the item was not found”. The source says the issue affects users who are running Windows 10 20H2 (Build 19042) as well as Windows 10 (2004) (Build 19041). This is probably due to the fact that both versions of the software platform use the same basic components.
The first reports of problems caused by the update appeared almost immediately after its release, and Microsoft is currently working on a solution. “ We are actively investigating. We apologize for the inconvenience, I suggest removing the update until the problem is resolved, ”a Microsoft representative commented on the issue.
According to the available data, removing KB4571756 does indeed fix the WSL startup issue. However, this security update is required to install, so there is no guarantee that it will not be forced to re-install. Of course, removing security updates is hardly a good solution, but there is currently no other way to fix the problem. As for the problems with installing the patch, they can be solved by using the Media Creation Tool utility.