Microsoft says some users may have issues enabling Smart App Control after installing this month’s Windows 11 security update KB5127648.
Smart App Control is a Windows 11 security feature that leverages Microsoft’s App Intelligence Services and Code Integrity features, working with Microsoft Defender and SmartScreen to block potentially malicious apps or binaries.
According to the company, the Smart App Control option is grayed out and cannot be toggled on affected devices running Windows 11, version 24H2 and later.
“After installing this update, some devices may not be able to enable Smart App Control in the Windows Security app if it has been disabled. On affected devices, the option to enable Smart App Control may be grayed out,” Microsoft said in an update KB5127648 notice.
“Devices for which Smart App Control is already activated are not affected and remain protected.”
Although a fix is not yet available, Microsoft has provided temporary workarounds to help IT administrators mitigate the issue on company-managed devices by changing the registry or installing a Group Policy.
To restore the ability to enable Smart App Control on affected Windows 11 devices by editing the registry, you must follow the steps below:
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Open a command prompt window by typing cmd in the Seek Crate.
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Select Run as administrator.
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At the command prompt, enter the following commands and then restart the device:
reg add "HKLM\SYSTEM\CurrentControlSet\Policies\Microsoft\FeatureManagement\Overrides" /v 2883193997 /t REG_DWORD /d 1 /f reg add "HKLM\SYSTEM\CurrentControlSet\Policies\Microsoft\FeatureManagement\Overrides" /v 2850574478 /t REG_DWORD /d 1 /f
IT administrators can also work around the issue by installing and configuring the following two Group Policies to enable Smart App Control and ensure troubleshooting logging is enabled:
The two group policies can be found under Computer Configuration > Administrative Templates > {Group Policy Name} > Windows 11, Version 24H2, 25H2.
After installation, administrators must set both settings to Enables and restart the affected devices to apply the Group Policy settings.
This week, Microsoft also confirmed that recent Windows updates cause Remote Desktop errors for non-admin users when the Admin Protection security feature is enabled, and fixed another known issue that resulted in Always On VPN connection issues after installing the September 2026 security updates.
On Tuesday, a bug was also fixed that caused black screens, problems loading the desktop and crashes in Explorer after installing Windows 11 updates released since August.
