KB5121003 crashes ARC Raiders and THE FINALS on Windows 11 via inpoutx64.sys (August 16, 2026)
Chapters
What the crashes look like
The pattern reported to Windows Latest is a game that will not stay running after KB5121003. It freezes during launch, or it closes without notice mid-session. Two error strings come up repeatedly: 'Hang detected on GameThread' and EXCEPTION_ACCESS_VIOLATION.
Some machines go further than losing the game. Reports include the PC restarting on its own and screens dropping to black. Three titles are named so far: ARC Raiders, THE FINALS and MARVEL Tokon: Fighting Souls.
The builds involved are the August ones, 26200.9168 on Windows 11 25H2 and 26100.9168 on 24H2. Every affected machine in these reports had the August security update installed.
TL;DR
On Windows 11, the August update KB5121003 started crashing ARC Raiders, THE FINALS and MARVEL Tokon: Fighting Souls with EXCEPTION_ACCESS_VIOLATION, according to Windows Latest on August 16, 2026. The factor the affected PCs share is inpoutx64.sys, a third-party kernel-level port-access driver that ships with RGB lighting and hardware utilities. There is no fix as of August 16, 2026, and Microsoft has not opened a known issue for it.
- Games freeze at launch or close without warning, showing 'Hang detected on GameThread' or EXCEPTION_ACCESS_VIOLATION. In the worst reports the PC restarts or drops to a black screen.
- Named games: ARC Raiders, THE FINALS and MARVEL Tokon: Fighting Souls, on builds 26200.9168 (25H2) and 26100.9168 (24H2).
- PCs without inpoutx64.sys are not affected, which is why the crashes look random from the outside.
- The workaround is stopping and deleting the inpoutx64 service and its driver file, at the cost of whatever RGB or fan-control feature needed it.
- As of August 16, 2026 there is no fix and no Microsoft known-issue entry.
The one thing affected PCs have in common
Windows Latest ties the crashes to a single file: inpoutx64.sys, a third-party kernel-level port-access driver. It is not a Microsoft component and it is not part of any game. It arrives with RGB lighting and hardware utilities, which install it because they need direct port access to the hardware they control.
That is what makes the failure look arbitrary. Two people with the same GPU, the same game and the same build get different results, because one of them installed a lighting utility a year ago and the other did not. The driver runs in the kernel, which fits the harsher outcomes in these reports: a fault there does not stay inside the game process.
What is not established on August 16, 2026 is which side changed. Windows Latest identifies the driver as the culprit, but there is no published account of what in the August update stopped working with it. Nobody has named the component, the function or the intended change.
| Detail | Value |
|---|---|
| Update | KB5121003, released August 11, 2026 |
| Builds | 26200.9168 (25H2), 26100.9168 (24H2) |
| Games named | ARC Raiders, THE FINALS, MARVEL Tokon: Fighting Souls |
| Errors | 'Hang detected on GameThread', EXCEPTION_ACCESS_VIOLATION |
| Driver implicated | inpoutx64.sys, in C:\Windows\System32\drivers |
| Microsoft known issue | None as of August 16, 2026 |
What Microsoft has published about KB5121003
The Microsoft Support article for the update, dated August 11, 2026, covers Windows 11 25H2 and 24H2 in all editions and carries the servicing stack update KB5123304 with it. It also records a change people will notice for other reasons: the Drop Tray experience is removed, along with its setting under Settings, then System, then Multitasking.
What that article does not contain on August 16, 2026 is the game crashes. There is no known-issue entry for them, no acknowledgement on release health, and therefore no Microsoft workaround and no fix date. Every instruction in circulation today comes from users and from the outlets collecting their reports.
Other faults reported in the same update
The crashes are the loudest complaint, but they are not the only one attached to KB5121003. Windows Latest also lists Windows Hello PIN sign-in failing and needing re-enrollment after a reboot, HDR breaking, and display refresh rates dropping without being asked.
Those are separate reports with separate symptoms, and removing the inpoutx64 driver has not been reported to change any of them. I am keeping them apart here rather than folding everything into one bug, because the evidence for a shared cause does not exist.
What you can do today
If a named game is crashing on a PC that has the August update, the driver is the thing to check. In order:
1. Look for the file. Open C:\Windows\System32\drivers and check whether inpoutx64.sys is there. If it is not, this is not your problem and removing anything will not help.
2. Open Command Prompt as administrator, then run sc stop inpoutx64 and then sc delete inpoutx64.
3. Delete C:\Windows\System32\drivers\inpoutx64.sys.
4. Restart the PC and launch the game again.
5. Understand the cost before step 2. The RGB lighting or fan-control utility that installed the driver loses the function that needed it. If you reinstall that utility later, check whether it puts the driver back.
6. Do not uninstall KB5121003 to keep playing. Windows Latest describes the update as addressing up to 400 security issues, and trading those away for a game is the wrong side of that deal.
7. If you would rather not remove a kernel driver by hand: Get XLAnt.
Frequently asked questions
How do I know whether inpoutx64.sys is the reason my game crashes?
Check whether the file exists in C:\Windows\System32\drivers on a PC running build 26200.9168 or 26100.9168. The reports tying the crashes to KB5121003 all involve that driver, and machines without it were not affected.
Has Microsoft confirmed the crashes?
Not as of August 16, 2026. The KB5121003 support article lists no known issue for them. The identification of inpoutx64.sys comes from user reports gathered by Windows Latest.