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Windows PC Errors

How to Fix App Crash 0xC0000409 (STATUS_STACK_BUFFER_OVERRUN)

By ErrorFix · Updated October 17, 2026 · 6 min read

Error 0xC0000409Plain English: the app crashed because it wrote data past the end of its allotted memory — a buffer overrun that Windows treats as a security threat and shuts the program down immediately.
Quick answer: Repair or reinstall your Microsoft Visual C++ Redistributables first — they are the most common trigger. Then run sfc /scannow, update your graphics and chipset drivers, and check whether DEP or your antivirus is killing the app. A clean boot finds conflicting software; reinstalling the crashing app clears corrupted program data.

What error 0xc0000409 means

Error code 0xc0000409 is the Windows status code STATUS_STACK_BUFFER_OVERRUN. When a program runs, it stores its short-term working data on a structure called the stack — think of it as a scratch pad with fixed-size slots. If the program tries to write more data than its slot can hold, it spills over into neighboring memory. That spill is called a buffer overrun, and Windows detects it and terminates the program on the spot.

The shutdown is deliberate protection. Buffer overruns are the same technique that malware uses to hijack programs, so Windows would rather crash a legitimate app than risk letting corrupted memory execute. You will usually see the crash as a dialog reading "The exception unknown software exception (0xc0000409) occurred in the application," followed by the program closing. It can strike when the app launches, when you use a particular feature, or even when you quit — close-time crashes are a classic pattern with this code. Games, office apps, and browsers all hit it from time to time, and the actual culprit is rarely the app itself: it is usually a broken shared component such as a Visual C++ runtime, a bad driver, or an overzealous security tool.

Common causes

How to fix error 0xc0000409 — step by step

Work through these fixes in order. Start with the shared runtimes, since they fix the majority of cases.

  1. Repair or reinstall the Microsoft Visual C++ Redistributables. Open Settings, then Apps, then Installed apps, and search for "Microsoft Visual C++". You will usually see several entries, such as 2015–2022 for both x64 and x86. Click the three-dot menu on each one, choose Modify, and click Repair. If the crash survives, uninstall every Visual C++ entry, download the latest supported redistributables from Microsoft's official site, reinstall both the x86 and x64 packages, and reboot your PC before testing the app again.
  2. Repair Windows system files with SFC and DISM. Right-click Start and choose Terminal (Admin). Type sfc /scannow and press Enter, then restart your PC when the scan finishes. If the app still crashes, open the same admin terminal and run DISM.exe /Online /Cleanup-image /Restorehealth, wait for it to complete, and then run sfc /scannow one more time. These tools repair the shared system libraries and the component store that crashing apps depend on.
  3. Update your graphics and chipset drivers. Open Device Manager, expand Display adapters, right-click your GPU, and choose Update driver. For the best result, download the newest driver from the NVIDIA, AMD, or Intel website and perform a clean install rather than relying on Windows Update. Do the same for your chipset drivers. Drivers inject code into running apps, and a faulty one is a classic source of stack overrun crashes.
  4. Add the app to the Data Execution Prevention exception list. Open the Start menu, search for "View advanced system settings", and open it. On the Advanced tab, under Performance, click Settings. Go to the Data Execution Prevention tab, select "Turn on DEP for all programs and services except those I select", click Add, and pick the crashing app's main .exe file. Click Apply and OK, then restart and test the app. This keeps DEP protection everywhere while letting the one misbehaving app run.
  5. Temporarily disable antivirus or add an exclusion. Third-party antivirus tools hook into process memory in ways that can trigger the same protections that kill apps with 0xc0000409. Disable real-time protection for ten to fifteen minutes and launch the app to see if it runs. If it does, do not leave protection off permanently. Instead, add the app's installation folder to your antivirus exclusion list, then re-enable real-time protection.
  6. Perform a clean boot to find conflicting software. Press Win + R, type msconfig, and open System Configuration. On the Services tab, check "Hide all Microsoft services", then click Disable all. Open the Startup tab, launch Task Manager, and disable every startup item. Restart your PC. If the app now runs, re-enable services and startup items in small batches, restarting between rounds, until the error returns. The last batch you re-enabled contains the conflicting program. Pay special attention to game overlays, screen recorders, and utility tools that inject into other apps.
  7. Reinstall the app and clear its leftover data. Uninstall the crashing app from Settings, then delete its leftover folders under %localappdata% and %appdata%, which hold cache, settings, and profile data that a normal uninstall leaves behind. Download a fresh copy of the app from the official source and install it. This wipes corrupted configuration and cached files that survive a plain reinstall.

Did this fix it? Quick checklist

If the error persists after all seven steps, open Event Viewer and look at the Application Error entry for the crash — the "Faulting module name" line tells you exactly which DLL triggered it, narrowing the search to one program, driver, or runtime. Also check whether the error began right after a Windows update; rolling back that update from Settings > Windows Update > Update history > Uninstall updates has resolved stubborn cases. As a last resort, do a repair install (an in-place upgrade using Media Creation Tool media, keeping your files and apps) — it replaces every Windows component while leaving your data intact.

Frequently asked questions

What does error 0xc0000409 mean?

Error 0xc0000409 is the Windows status code STATUS_STACK_BUFFER_OVERRUN. It means the app wrote data past the end of its reserved memory stack. Windows treats this as dangerous, because it is the same technique malware uses, and kills the app immediately instead of letting the corrupted memory run.

Why does 0xc0000409 appear when I close a program?

This is a very common pattern: the app itself ran fine, but its shutdown code hit a buffer overrun while cleaning up. Repairing the Visual C++ runtimes and reinstalling the app fixes most close-time crashes, because the faulty cleanup code usually lives in a shared runtime library rather than the app.

Is 0xc0000409 caused by a virus?

Almost never. It is a memory-handling fault, usually caused by broken shared components, bad drivers, or conflicting software. Still, run one full antivirus scan while troubleshooting, since malicious code can also trigger buffer-overrun detections and it is worth ruling out.

Will disabling DEP fix 0xc0000409?

It can stop the symptom, but turning DEP off system-wide removes a real security layer. The safer move is the one in step 4: add only the affected app to the DEP exception list so protection stays on for everything else.

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