**Microsoft** has officially resolved a persistent issue that hindered some users from enabling **Smart App Control** after installing the October 2026 **KB5127648 Windows 11** security update. **Smart App Control** is a vital security component that leverages **Microsoft**'s code integrity features and app intelligence services. It works in conjunction with **SmartScreen** and **Microsoft Defender** to proactively block potentially malicious applications and binaries. ### The Glitch: Grayed-Out Activation As previously acknowledged by the company, the **Smart App Control** option was rendered inaccessible, appearing grayed out on affected devices running **Windows 11 24H2** and later versions. "After installing this update, some devices might be unable to turn on **Smart App Control** in the Windows Security app if it has been turned off. On affected devices, the option to turn on **Smart App Control** might be grayed out," **Microsoft** stated in the **KB5127648** advisory. The company clarified that devices where **Smart App Control** was already active remained protected. ### Resolution and Update Details On Wednesday, **Microsoft** confirmed that the issue has been rectified for users who installed this month's **KB5127936** preview update. "This issue was resolved by Windows updates released October 28, 2026 [...] and later. We recommend you install the latest security update for your device as it contains important improvements and issue resolutions, including this one," an alert to IT administrators noted. ### Workaround for Administrators For administrators who prefer not to deploy preview updates on enterprise-managed devices and wish to wait for next month's Patch Tuesday cumulative updates, **Microsoft** has provided a temporary fix. This workaround involves editing the registry on affected **Windows 11** devices to restore the ability to enable **Smart App Control**. The steps are as follows: 1. Open a Command Prompt window by typing `cmd` in the Search box. 2. Select Run as Administrator. 3. At the command prompt, enter the following commands and then restart the device: Alternatively, administrators can apply specific Group Policies that activate **Smart App Control** and enable logging for troubleshooting purposes. These include: * [Windows 11, versions 24H2, 25H2, and 26H2 - KB5074105 261015_19222 Feature Preview](https://download.microsoft.com/download/0a6cd6b8-5238-4129-bf2f-9d2a1edde053/Windows%2011%2024H2%2c%20Windows%2011%2025H2%20and%20Windows%20Server%202025%20KB5074105%20261015_19222%20Feature%20Preview.msi) * [Windows 11, versions 24H2, 25H2, and 26H2 - KB5074105 261015_19221 Feature Preview](https://download.microsoft.com/download/b0e50eea-931f-49e9-be90-6d6268e94721/Windows%2011%2024H2%2c%20Windows%2011%2025H2%20and%20Windows%20Server%202025%20KB5074105%20261015_19221%20Feature%20Preview.msi) The Group Policy settings are located under `Computer Configuration > Administrative Templates > {Group Policy name} > Windows 11, version 24H2, 25H2,` and must be set to **Enabled** after installation. A device restart is also required to apply these settings. Beyond the **Smart App Control** fix, the **KB5127936** preview update also addresses other critical issues, including **Remote Desktop** failures caused by recent **Windows** updates when the "Administrator protection" security feature is enabled, and finally resolves **Always On VPN** issues triggered by the September 2026 cumulative updates.