Microsoft recently released July's Windows 11 Patch Tuesday Update KB5015814 which featured the usual security fixes, and, one big tweak related to PowerShell, and the new Search Highlights feature. Yet it now seems that the update is causing headaches for a small set of users, who are taking to social media to vent their Windows frustrations (via Neowin.)
According to comments from some users on Reddit, the update seems to be quite troublesome, throwing up all kinds of error codes. One Redditor mentions that the update straight-up fails to install with a specific error code of 0x8000ffff. Another one mentioned error code 0x80073701. And in some instances, people have mentioned that the Start Menu also can't even pen and close properly, as it is interrupted by an app after installing the update. At the worst, some people even have said that their computer doesn't boot right, going into a boot loop instead.
Microsoft hasn't updated the changelogs for this latest patch to mention any of these issues. As usual, it's best to report the issues using Feedback Hub, and not social media so Microsoft can bring them to the right teams to be addressed. In this case, though, the issue might be isolated and not a major one, as it seems as though the app Malwarebytes could be what is causing this.
At any rate, if you happen to get this update on your PC, which you probably will since it's automatic, you might want to uninstall it if you face issues. You also can pause Windows Update to skip this one for now. Let us know in the comments below if you've had issues.