Codex crashes on launch with HEAP_CORRUPTION when Windows Store update is detected but cannot be downloaded

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

26.519.2736.0 (Microsoft Store)

What subscription do you have?

Plus

What platform is your computer?

Windows 11 Enterprise (10.0.22631)

What issue are you seeing?

Codex Desktop (Microsoft Store version) crashes immediately on launch with a segmentation fault when it detects a newer version available on the Microsoft Store but cannot download it due to network restrictions.

This creates a recurring cycle: updating to the latest msix package fixes the issue temporarily, but the crash returns once the Store pushes another newer version that the app detects but cannot download.

What steps can reproduce the bug?

1. Install Codex from Microsoft Store (or via msix)
2. Wait until Microsoft Store publishes a newer version than the installed one
3. Be on a network that blocks access to the Microsoft Store
4. Launch Codex
5. Codex window does not appear; process exits silently

What is the expected behavior?

Codex should launch normally regardless of whether a Store update is available or whether the Store is reachable.

Additional information

Bug: Codex crashes on launch with HEAP_CORRUPTION when Windows Store update is detected but cannot be downloaded

Description

Codex Desktop (Microsoft Store version) crashes immediately on launch with a segmentation fault when it detects a newer version available on the Microsoft Store but cannot download it due to network restrictions.

This creates a recurring cycle: updating to the latest msix package fixes the issue temporarily, but the crash returns once the Store pushes another newer version that the app detects but cannot download.

Environment

• OS: Windows 11 Enterprise (10.0.22631)
• Codex Version: 26.519.2736.0 (Microsoft Store)
• Package Identity: OpenAI.Codex_26.519.2736.0_x64__2p2nqsd0c76g0
• Network: Corporate network that blocks access to Microsoft Store
• Electron: 42.1.0
• Node: 24.15.0
• GPU: Intel(R) UHD Graphics (driver 31.0.101.4255)

Steps to Reproduce

1. Install Codex from Microsoft Store (or via msix)
2. Wait until Microsoft Store publishes a newer version than the installed one
3. Be on a network that blocks access to the Microsoft Store
4. Launch Codex
5. Codex window does not appear; process exits silently

Expected Behavior

Codex should launch normally regardless of whether a Store update is available or whether the Store is reachable.

Actual Behavior

Codex's CLI backend process (app/resources/codex.exe) crashes with a heap corruption error. The main Electron window is never created.

Evidence

Windows Event Viewer (Application Error)

Faulting application name: codex.exe, version: 0.133.0.0
Faulting module name: ntdll.dll, version: 10.0.22621.6345
Exception code: 0xc0000374
Fault offset: 0x000000000010d689
Faulting application path: C:\Program Files\WindowsApps\OpenAI.Codex_26.519.2736.0_x64__2p2nqsd0c76g0\app\resources\codex.exe
Faulting package full name: OpenAI.Codex_26.519.2736.0_x64__2p2nqsd0c76g0

Exception code 0xc0000374 = STATUS_HEAP_CORRUPTION

Codex Application Log

On a successful launch (when no Store update is pending), the log shows:

[AppServerConnection] app_server_connection.state_changed ... currentState=connecting ...
[IpcRouter] I am the router
[window-manager] window ready-to-show appearance=primary ...

On a failed launch (Store update detected but cannot be downloaded), the log stops after:

[windows-store-updater] Checking Windows Store for package updates buildVersion=26.519.2736.0 manifestBuildVersion=26.519.3891.0 packageIdentity=OpenAI.Codex
[AppServerConnection] app_server_connection.state_changed ... currentState=connecting ...

The IpcRouter and window-manager entries never appear. The process crashes immediately after the AppServer connection is established.

Launch from Command Line

$ "/c/Program Files/WindowsApps/OpenAI.Codex_26.519.2736.0_x64__2p2nqsd0c76g0/app/Codex.exe"
# ... startup logs ...
[AppServerConnection] app_server_connection.state_changed ... currentState=connecting ...
Segmentation fault

Correlation Data (same day, 24 launch attempts)

| Store updater check | Window created | Count |
|---------------------|----------------|-------|
| Yes | Yes | 3 |
| Yes | No (crash) | 18 |
| No (subprocess) | No | 1 |

The 3 successful launches occurred earlier in the day before the crash pattern stabilized. After that, every launch attempt resulted in the same crash.

Log path: %LOCALAPPDATA%\Packages\OpenAI.Codex_2p2nqsd0c76g0\LocalCache\Local\Codex\Logs\

Workaround

Install the latest Codex msix package manually. This clears the "update available" state and Codex launches normally. However, the crash recurs once the Store publishes another newer version.

Suspected Root Cause

The windows-store-updater module detects a newer version via manifestBuildVersion but cannot complete the download due to network restrictions. This "update pending but download failed" state appears to corrupt the heap in the CLI backend process (codex.exe, a native Rust/C++ binary), causing the STATUS_HEAP_CORRUPTION crash in ntdll.dll.

The relevant log line is:

[windows-store-updater] Checking Windows Store for package updates buildVersion=26.519.2736.0 manifestBuildVersion=26.519.3891.0 packageIdentity=OpenAI.Codex

After manually updating to 26.519.3891.0, the windows-store-updater check no longer appears in the logs (no newer version detected), and Codex launches successfully.

Additional Notes

• This issue is particularly impactful for users in corporate/enterprise environments where Microsoft Store access is commonly blocked
• The --disable-gpu flag does not work around this issue — the crash occurs regardless
• Clearing Electron cache directories does not work around this issue
• The crash is in the native codex.exe backend, not the Electron renderer process