Windows 11 update KB5121003 causes game crashes

Microsoft’s August 2026 security update for Windows 11 (KB5121003) is causing significant technical issues for users, particularly gamers. While the patch addresses over 400 vulnerabilities, it has been linked to sudden game crashes, system restarts, and blue screens.

Embark Studios has confirmed that titles such as ‘ARC Raiders’ and ‘The Finals’ are experiencing instability. The root cause appears to be an incompatibility between the update and the third-party kernel-level driver ‘inpoutx64.sys’, which is often installed by hardware utility tools like the Razer Update Tool.

Beyond gaming, some users have reported issues with Windows Hello, black screens, and erratic HDR performance. Microsoft has not yet officially listed these specific incidents as known issues. A temporary workaround involves using the Command Prompt as an administrator to stop and delete the ‘inpoutx64.sys’ driver file, though users are cautioned that uninstalling the entire update would remove critical security protections.