Home windows 11 KB5121003 is August 2026’s massive safety replace that fixes over 400 safety points, but it surely’s inflicting main points for some video games. Avid gamers instructed Home windows Newest that ARC Raiders and The Finals are among the many video games that crash after putting in the obligatory replace, and the sport studio behind each titles says the Home windows Replace is accountable.
“We’re conscious of a brand new crash launched with the discharge of a Home windows replace (KB5121003) which may be affecting a few of you,” Embark, the studio behind ARC Raiders, wrote in a message on Discord, as first noticed by Home windows Newest. “The workforce is engaged on a repair, and we’ll maintain you posted on any updates.”
KB5121003 is a compulsory Home windows Replace launched on August 11, and it advances PCs to Construct 26200.9168 for those who’re on model 25H2, and 26100.9168 for these on 24H2. If you happen to’re undecided what construct you’re operating, you may open Settings > System > About and discover the OS construct quantity.
We’ve been testing the August 2026 Update throughout our machines, and we’ve not noticed any main issues to date. Within the official release notes, Microsoft additionally says it isn’t conscious of any points with the replace.
Nonetheless, person stories inform us a unique story, and Embark’s assertion additionally confirms that there’s one thing mistaken with Home windows 11 KB5121003, not less than on some PCs.
Home windows 11 KB5121003 is crashing video games on some PCs
Shortly after the August 2026 Replace rolled out, we began getting messages from players, significantly those that play ARC Raiders, saying their recreation immediately began crashing.
At first, I puzzled if it was as a consequence of a current driver replace, as we’ve had comparable stories prior to now the place Nvidia or AMD triggered points and the blame shifted to Microsoft. However this time, it appears to be like like Home windows 11 KB5121003 made a change that broke compatibility with a driver referred to as inpoutx64.sys.
As some users noted on Reddit, ARC Raiders began crashing after the replace was put in, and there are additionally stories of system reboots when it occurs. One gamer reported six crashes, with a few of them instantly rebooting Home windows.
Home windows Newest beforehand confirmed that the August 2026 Update itself can cause multiple reboots during installation as a result of Safe Boot certificates rollout, however that’s totally different. These reboots occur whereas the replace is being put in, not whilst you’re enjoying a recreation.
If you happen to’re affected, you may even see totally different errors, however stories we’ve seen embody “Dangle detected on GameThread” and EXCEPTION_ACCESS_VIOLATION after Home windows 11 KB5121003 was put in.
Till now, it was unclear what broke video games reminiscent of ARC Raiders, which labored alright till just a few days in the past, however Embark has now shed some gentle on the issue.
Home windows 11 KB5121003 seems to have damaged compatibility with inpoutx64.sys
It seems that Home windows 11 KB5121003 seems to have made a change that affected compatibility with inpoutx64.sys, which is a third-party kernel-level port entry driver utilized by some {hardware} utilities and different apps.
“It is a crash associated to the file inpoutx64.sys, which modified with the Home windows replace,” Embark noted in a Discord put up. “We’re working in the direction of a long-term repair, however within the meantime there’s a workaround resolution that can safely take away the file in query and let you play the sport with out subject.”
Embark additionally shared the next workaround for affected customers:
- Open the Begin menu in Home windows and kind ‘cmd’ to search out the Command Immediate.
- Proper-click on the Command Immediate and choose ‘Run as Administrator’.
- Within the Command Immediate window, sort ‘sc cease inpoutx64’.
- Press Enter.
- Then sort ‘sc delete inpoutx64’ and press Enter. Shut the window.
- Open File Explorer and navigate to C:WindowsSystem32drivers.
- Find the file inpoutx64.sys and delete the file.
Embark’s discovering aligns with what we’re hearing from players. For instance, one ARC Raiders person who investigated their very own crashes discovered that inpoutx64.sys had been put in by a Razer Replace Software.
That person discovered that merely disabling the inpoutx64 service and restarting the PC was sufficient to cease the crashes on their machine. Nonetheless, Embark’s official workaround goes additional by stopping and deleting the service and eradicating inpoutx64.sys.
Proper now, we don’t know precisely what Home windows 11 KB5121003 modified that broke compatibility with inpoutx64.sys, however we’ll probably hear again from Microsoft quickly.
A number of affected customers additionally say eradicating Home windows 11 KB5121003 resolves the difficulty, which confirms there’s a compatibility drawback between the replace and the driving force.
We’re seeing similar crash reports involving different video games, together with Marvel Tōkon: Preventing Souls. Home windows Newest has additionally seen stories of some anti-cheat-related software program crashing, however all the pieces goes again to regular when the replace is eliminated.
Home windows 11 August 2026 Replace can be inflicting different points
The Home windows 11 August 2026 Replace features a lengthy listing of enhancements and fixes, together with display-related modifications. That additionally means it’s attainable Microsoft might have unintentionally created points on some PCs.
For instance, we’ve come throughout stories of display refresh rates unexpectedly dropping, black screens, broken HDR behavior, and different graphics-related issues.
Home windows Newest can be seeing remoted stories of Home windows Whats up issues after Home windows 11 KB5121003, together with a case the place PIN credentials must be re-enrolled after each reboot and one other report the place Home windows fails to load the prevailing Home windows Whats up container.
“After putting in KB5121003 (construct 26100.9168/26200.9168), Home windows Whats up PIN sign-in fails on each single reboot, forcing me to reconnect to my Microsoft account to re-enroll the PIN every time,” one person instructed Home windows Newest in an electronic mail.
“Home windows deletes and recreates the important thing every reboot (totally different key GUID each time), however the brand new key turns into corrupted once more by the following boot, an infinite loop.”
What to do when you have points with Home windows 11 KB5121003?
If video games will not be working after the replace, you may strive nuking the inpoutx64 driver or finding the software program that added the driving force to your system. When you have different points, your finest guess is to take away the August patch by going to Settings > Home windows Replace > Replace historical past > Uninstall updates.
Eradicating Home windows 11 KB5121003 has labored for customers who’ve run into these points, however I don’t suggest uninstalling it until the issues are critical sufficient to make your PC unusable.
The August 2026 Replace is a vital launch, as it patches up to 400 security issues, and Microsoft has warned towards delaying updates previous three days. There are a number of crucial bugs addressed on this replace, together with a zero-day vulnerability generally known as “LegacyHive,” which provides hackers admin privileges if exploited.
It’s best to ideally anticipate a repair, Microsoft’s assertion, or the September 2026 Replace. Except your PC is unusable, I’d suggest you keep away from eradicating these month-to-month patches as a consequence of rising AI-powered threats.
