- Status: Confirmed / Unresolved
- Affected Versions: Windows 11 (24H2)
- KB Article: KB5121003
Microsoft released its major August security update, KB5121003, last week to address over 400 security vulnerabilities across Windows 11. While the patch is essential for maintaining system security, a growing number of users are reporting severe stability issues following installation. According to reports from Windows Latest, the update is triggering unexpected game crashes, graphics corruption, and even Windows Hello login failures for a subset of PC owners.
For those considering whether to install the patch now, it is important to understand the specific conflicts it introduces. The issues appear to stem from a compatibility break with a specific system driver rather than a broad kernel failure, though the symptoms can be disruptive enough to make uninstallation a tempting option.
#1 The inpoutx64.sys Conflict and Game Crashes
The most widely reported problem involves games crashing unexpectedly, with titles from Embark Studios—specifically ARC Raiders and The Finals—being particularly affected. Embark has confirmed via Discord that these crashes are not caused by a game-side update or a standard graphics driver issue.
Instead, the root cause appears to be a conflict with a driver file named inpoutx64.sys. This driver is typically associated with hardware peripherals that require direct access to I/O ports, such as certain arcade sticks, MIDI controllers, or specialized input devices. When KB5121003 is applied, it seems to compromise the stability of this driver, leading to system-level crashes while gaming.
Users affected by this conflict report experiencing multiple crashes in a single session. In some instances, Windows will restart immediately following a crash. Error messages displayed during these events often include Hang detected on GameThread or EXCEPTION_ACCESS_VIOLATION, indicating that the system encountered an invalid memory access triggered by the driver incompatibility.
If you own hardware that relies on inpoutx64.sys, this update may cause immediate disruption to your gaming setup. Even if you do not actively use such peripherals, the driver may still be present on your system from previous installations.
#2 Graphics Glitches and Windows Hello Failures
Beyond gaming, the August patch is causing broader system instability. Users have reported sudden drops in display refresh rates, persistent black screens, and faulty HDR behavior. These graphics-related issues suggest that the update is interfering with how the operating system manages display output and color profiles.
Perhaps more frustrating for daily users is an isolated but persistent issue with Windows Hello. Reports indicate that the stored sign-in key for PIN authentication is being deleted or corrupted upon system restart. This means affected users are forced to re-register their PIN every time they sign in, which is a significant usability regression.
These symptoms point to a patch that, while successful in patching security holes, has introduced regressions in driver handling and authentication storage. Microsoft has not yet publicly acknowledged these specific issues, leaving users to rely on community-sourced workarounds.
#3 Workarounds and How to Proceed
If you are experiencing crashes related to inpoutx64.sys, Embark Studios has provided a potential fix. You can attempt to disable the driver by opening the Windows Command Prompt as an administrator and entering the following commands:
sc stop inpoutx64sc delete inpoutx64
After running these commands, navigate to C:\Windows\System32\drivers in File Explorer and delete the inpoutx64.sys file. In some cases, simply stopping the service may be sufficient to prevent crashes without permanent removal.
For users severely affected by the broader issues, including the Windows Hello and display bugs, uninstalling the update is an option. You can do this by going to Settings → Windows Update → Update history → Uninstall updates. However, this should be a last resort, as it will leave your system exposed to the 400+ vulnerabilities that KB5121003 was designed to fix.
What This Means for You
The release of KB5121003 highlights the ongoing challenge of balancing rapid security patching with hardware compatibility. If your PC is not currently affected by these issues, it may be wise to wait for Microsoft to release a corrective update before installing. If you rely on peripherals that use inpoutx64.sys, test the workaround carefully to ensure it resolves the crash without disabling your hardware functionality.
Source: PCWorld
Build details:
- kb5121003
Over to you: Have you experienced crashes or issues after installing KB5121003, and did the inpoutx64 workaround help?
