KB5121003: Windows 11 Version 25H2 Security Update (August 2026)

1. Reports of certain games becoming unresponsive

Symptoms

Microsoft received reports of issues involving inability to run certain games as expected after installing this update.

Ongoing investigation indicates that this issue is associated with certain peripherals or internal device components that support RGB lighting features. These devices might install drivers or software components with file names similar to inpoutx64 . On systems where these drivers are found, launching certain games can trigger this issue.

Games identified in reports of this issue include ARC Raiders, MARVEL Tōkon: Fighting Souls, and THE FINALS. Reported symptoms include:

the game application becomes unresponsive

the game application closes without notice

the error "EXCEPTION_ACCESS_VIOLATION" is displayed

the device restarts without warning

If you are experiencing this issue or a similar issue, please use Feedback Hub to submit a report. You can open Feedback Hub by pressing the Windows logo key + F . For additional information, see Send feedback to Microsoft with the Feedback Hub app . Your reports are helpful to our investigation.

Resolution

This issue is resolved by a block that prevents the inpoutx64 driver from loading on affected devices. When the block is applied, a message is displayed that states the driver has been disabled, after which the game will launch normally.

This resolution is available automatically to consumer and business devices that are not managed by IT departments. For enterprise-managed devices, the mitigation will not propagate automatically. IT administrators can follow the steps in the workaround section on the Windows release health site .

2. Microsoft Teams and Outlook might fail to launch on ARM-based devices

Symptoms

After installing Windows security updates released on or after August 11, 2026, (KB5121003) , Microsoft Teams and the new Outlook for Windows might fail to launch or might close unexpectedly on ARM-based devices, such as Surface Pro 11 and Surface Laptop 7. Classic Outlook, Word, Excel, and other applications are not known to be affected. This issue is most likely to occur on new or freshly imaged PCs that have not yet installed any Microsoft Store updates.

Workaround

To work around this issue:

Open Microsoft Store.

Select Downloads > Check for updates.

Install the latest update for the Auto Super Resolution Package (version 1.0.19.0 or later).

Resolution

This issue is resolved in Windows updates released on and after September 8, 2026 such as KB5124008 . We recommend you install the latest Windows update for your device as it contains important improvements and issue resolutions, including this one.