Microsoft's October Patch Tuesday update for Windows 11, rolled out on October 13, introduces a glitch that disables the ability to turn on Smart App Control. The security feature, added in 2022, blocks potentially malicious or suspicious apps and files. If the feature was already enabled before the update, it remains active; the problem only affects systems where it is currently off, as the toggle to switch it on becomes grayed out.
A ZDNET reporter verified the issue across three updated Windows 11 PCs, finding the option unavailable on all of them, while an unupdated machine still allowed the setting to be changed. Microsoft has acknowledged the bug and says it is working on a fix for a future release.
In the meantime, Microsoft has provided a workaround. Users can open a command prompt as administrator and add two registry keys under HKLM\SYSTEM\CurrentControlSet\Policies\Microsoft\FeatureManagement\Overrides. After rebooting, the Smart App Control settings screen should show the "On" option available again.
The article recommends keeping Smart App Control enabled for protection against unknown malware, though it notes the feature can interfere when installing files from unfamiliar sources. Until Microsoft ships a permanent fix, the registry edit offers a way to restore the security setting.