[Windows] Codex app crashes immediately on startup in chrome.dll with C0000005

What version of the Codex App are you using (From “About Codex” dialog)?

26.810.7004.0

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

Summary

The Codex desktop app crashes immediately on startup. No application window appears.

The crash occurs through both the normal AppX/Start menu entry and direct execution of the packaged ChatGPT.exe.

Environment

• Windows 11 Pro x64, build 26200
• Codex App package: OpenAI.Codex
• Package version: 26.810.7004.0
• AUMID: OpenAI.Codex_2p2nqsd0c76g0!App
• Embedded chrome.dll version: 151.0.7922.137
• ChatGPT Plus subscription

The previous package version 26.814.5167.0 also showed the same startup failure.

Steps to reproduce

1. Install the signed x64 MSIX package.
2. Launch Codex from the Start menu.
3. The process starts but exits immediately.
4. No application window is displayed.

Crash diagnostics

• Exit code: -1073741819 (0xC0000005)
• Exception: C0000005 ACCESS_VIOLATION
• Process: ChatGPT.exe
• Faulting module: chrome.dll
• Exception address: chrome!v8::Context::Exit+0x1b
• Attempted read address: 0x00000000000001F8
• Symbol: chrome+507535b
• Failure bucket: INVALID_POINTER_READ_c0000005_chrome.dll!Unknown
• Failure hash: {5cd13162-58f6-4190-dced-e6b658b0f99b}

The same exception address, call stack, and failure hash were captured when launching through the normal AppX entry and when launching the packaged executable directly.

Relevant stack frames:

chrome!v8::Context::Exit+0x1b
chrome!node::AsyncResource::CallbackScope::~CallbackScope
chrome!uv_fs_get_result
chrome!ChromeMain
ChatGPT.exe

Troubleshooting already completed

• Verified that the MSIX package and ChatGPT.exe digital signatures are valid.
• Confirmed that the package status is OK.
• Reinstalled the application.
• Reproduced the crash using two Windows user accounts, including a newly created clean account.
• Tested with GPU acceleration disabled; the crash was unchanged.
• Confirmed that AppX, licensing, and Microsoft Store services are running.
• Confirmed that Microsoft Edge WebView2 Runtime is installed.
• No third-party DLL injection was visible in the captured process.
• NTGLOBALFLAG and Application Verifier flags were both zero.

Expected behavior

The Codex desktop app should open and display its main window.

Actual behavior

ChatGPT.exe starts and immediately terminates with a C0000005 access violation in the bundled chrome.dll, before displaying a window.

What steps can reproduce the bug?

1. Install the signed Codex x64 MSIX package.
2. Confirm that the OpenAI.Codex package is registered successfully and its status is Ok.
3. Launch Codex from the Windows Start menu.

The problem can also be reproduced with the following AppX activation command:

explorer.exe shell:AppsFolder\OpenAI.Codex_2p2nqsd0c76g0!App

The ChatGPT.exe process starts but terminates immediately. No application window appears.

The issue reproduces every time and also occurs in a newly created clean Windows user account.

What is the expected behavior?

The Codex desktop application should start normally and display its main window.

Additional information

The process exits with code -1073741819 (0xC0000005).

A ProcDump crash dump analyzed with WinDbg shows:

• Exception: C0000005 ACCESS_VIOLATION
• Process: ChatGPT.exe
• Faulting module: chrome.dll
• Exception address: chrome!v8::Context::Exit+0x1b
• Attempted read address: 0x00000000000001F8
• Failure bucket: INVALID_POINTER_READ_c0000005_chrome.dll!Unknown
• Failure hash: {5cd13162-58f6-4190-dced-e6b658b0f99b}
• Embedded chrome.dll version: 151.0.7922.137

The same exception address, call stack, and failure hash were captured through both normal AppX activation and direct executable launch.

Package signatures are valid, GPU acceleration was disabled for testing, required AppX and licensing services are running, and the problem reproduces in two Windows user accounts.

The previous package version 26.814.5167.0 also failed to start.

Start by reproducing the failure through the AppX activation command and direct ChatGPT.exe launch, then inspect the supplied ProcDump/WinDbg crash details for chrome.dll. Compare the startup behavior across the reported package versions and clean Windows accounts. Done means the signed Codex package launches without the C0000005 crash and displays its main window.