[Windows 11 25H2][26.915.4065.0] Desktop app stuck at login while codex app-server crashes with 0xC0000005

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

26.915.4065.0

What subscription do you have?

Plus

What platform is your computer?

Microsoft Windows NT 10.0.26200.0

What issue are you seeing?

On Windows 11 Pro 25H2, the ChatGPT/Codex desktop app launches and remains open, but it cannot load/reach the login page and never completes startup.
The application itself does not visibly crash.

After troubleshooting, I isolated the underlying failure to the bundled codex.exe app-server: the normal Codex CLI works, but codex app-server consistently terminates with:
0xC0000005 / STATUS_ACCESS_VIOLATION
This occurs both with the default stdio transport and with an explicit local WebSocket listener.

Environment

• Windows 11 Pro 25H2
• OS release reported by Codex logs: 10.0.26200
• Architecture: x64
• Windows app package: OpenAI.Codex 26.915.4065.0
• Bundled Codex CLI: 0.155.0-alpha.9.2
• Installation: Microsoft Store / packaged Windows app

The ChatGPT web application works normally on the same computer and network, on Win10

User-visible symptom

The Windows desktop app starts and remains open, but gets stuck while attempting to load the sign-in/login page.
It never reaches a usable authenticated state.
Multiple ChatGPT processes may remain running in the background.

Minimal reproduction

The bundled Codex executable is:

```powershell
$codex = "C:\Users\<user>\AppData\Local\OpenAI\Codex\bin\<build>\codex.exe"

Normal CLI commands work:
& $codex --version
Output:
codex-cli 0.155.0-alpha.9.2
And:
& $codex --help works normally.

However:

& $codex app-server
$LASTEXITCODE

returns:
-1073741819
which corresponds to:

0xC0000005
STATUS_ACCESS_VIOLATION

The same failure occurs with an explicit WebSocket listener:

& $codex app-server --listen ws://127.0.0.1:8765
$LASTEXITCODE

Result:
-1073741819
Therefore the crash is not specific to the default stdio transport.

Desktop log behavior:

The desktop logs show that Codex can initially start and complete its initialization handshake:
Codex CLI initialized
but shortly afterwards the app-server terminates:
Codex CLI process exited ... code=3221225477
followed by errors such as:
write EPIPE
or:

Codex app-server websocket closed (code=3221225477)
3221225477 is 0xC0000005.

The desktop application then repeatedly attempts to restart/reconnect to the local app-server.

Troubleshooting already performed:

The problem persists after:

• Restarting Windows
• Windows app Reset
• Full uninstall and reinstall of the desktop app
• Deleting package-local ChatGPT/Codex application data
• Recreating the local Codex runtime
• Removing the complete %USERPROFILE%.codex directory and testing with a completely fresh Codex user state
• Rebuilding the bundled plugin cache
• Verifying that codex.exe has a valid OpenAI Authenticode signature
• Testing both stdio and WebSocket app-server transports
• Checking Windows Defender for Codex/OpenAI detections
• Checking WinHTTP proxy configuration
• Verifying DNS resolution
• Verifying TCP/443 connectivity to auth.openai.com and chatgpt.com

A fresh .codex directory does not change the behavior:
& $codex app-server
still immediately terminates with 0xC0000005.

Bundled plugin observation

Earlier desktop logs contained:

failed to load plugin: plugin is not installed
plugin: codex-app-tools@openai-bundled

The bundled marketplace itself was successfully staged, including:

codex-app-tools
browser
unified-computer-use
chrome
computer-use
latex
visualize

I manually populated the expected codex-app-tools cache directory as a diagnostic test.
This removed the original missing-plugin condition, but codex app-server continued to terminate with the same 0xC0000005.
Therefore the missing-plugin error appears to be secondary rather than the root cause.

Crash reporting

No corresponding normal Windows Application Error / Windows Error Reporting event for codex.exe is generated.
No Crashpad .dmp file is generated under the desktop application's Crashpad reports directory.
This differs from some other Windows 0xC0000005 reports where chrome.dll is identified as the faulting module.
I therefore cannot confirm that my failure originates in chrome.dll.

Expected behavior

codex app-server should remain running and allow the Windows desktop application to complete its initialization and authentication flow.

Actual behavior

codex app-server terminates immediately with 0xC0000005.
The Windows desktop application remains open but cannot complete the login/startup process.

Possibly related issues

• #45435 — Windows desktop startup crash with 0xC0000005 in chrome.dll
• #46644 — Codex Windows 0xC0000005 / Crashpad browser-process crash

My case appears related to the same general Windows native-crash family, but the visible symptom is different: the desktop window remains open while the bundled codex app-server crashes repeatedly.

What steps can reproduce the bug?

1. Launch the ChatGPT/Codex Windows desktop app on Windows 11 Pro 25H2.
2. The app window opens but cannot complete the login/startup flow.
3. Locate the bundled Codex CLI executable, for example:

```powershell
 $codex = "C:\Users\<user>\AppData\Local\OpenAI\Codex\bin\<build>\codex.exe"

4. Verify the CLI itself works:

& $codex --version
& $codex --help

5. Start the app-server directly:

& $codex app-server
$LASTEXITCODE

6. The process exits immediately with:
   -1073741819
   which corresponds to:
   0xC0000005 / STATUS_ACCESS_VIOLATION
7. The same happens with an explicit WebSocket transport:

& $codex app-server --listen ws://127.0.0.1:8765
$LASTEXITCODE

Result:
-1073741819

The issue reproduces consistently even after:

• full uninstall/reinstall of the Windows app
• deletion of package-local app data
• recreating the Codex runtime
• removing the entire %USERPROFILE%\.codex directory and testing with a fresh state
• rebuilding the bundled plugin cache
• verifying DNS/network connectivity to OpenAI
• testing both stdio and WebSocket app-server transports

The ChatGPT web app works normally on the same machine/network.

No session ID is available because the desktop app does not complete sign-in. Token-limit and context-window usage are not applicable because the failure occurs before a usable authenticated session is established.

What is the expected behavior?

The expected behavior is that the Windows desktop app launches normally, loads the sign-in page, allows authentication, and then reaches the main ChatGPT/Codex interface.
At the backend level, codex app-server should start successfully and remain running so the desktop app can communicate with it.
For example:

```powershell
& $codex app-server

should keep the app-server process alive instead of immediately terminating with 0xC0000005.

Likewise:
& $codex app-server --listen ws://127.0.0.1:8765
should start a local WebSocket listener and remain active until manually stopped.

The desktop app should not remain stuck on the login/startup screen, and the local app-server should not repeatedly terminate and restart.

Additional information

The issue appears to be specific to the local Codex app-server path rather than to the general CLI, network, or sign-in service.
Additional observations:

• codex.exe --version and codex.exe --help work normally.
• codex app-server consistently exits with 0xC0000005.
• The same crash occurs with both the default stdio transport and an explicit local WebSocket listener.
• The ChatGPT web app works normally on the same machine and network.
• DNS and TCP/443 connectivity to auth.openai.com and chatgpt.com are successful.
• No WinHTTP proxy is configured.
• The issue persists with a completely fresh %USERPROFILE%\.codex directory.
• The issue also persists after uninstalling/reinstalling the Windows app and clearing package-local application data.
• codex.exe has a valid OpenAI Authenticode signature.
• No normal Windows Application Error / WER crash entry is generated for codex.exe.
• No Crashpad dump is generated on this machine.

The desktop logs show that the Codex CLI can initialize successfully, but the app-server then terminates and the desktop app receives write EPIPE / Codex app-server websocket closed errors.

An earlier codex-app-tools@openai-bundled plugin warning was also investigated. The plugin was successfully staged and manually placed in the expected cache location, but the 0xC0000005 app-server crash remained unchanged, suggesting the plugin warning is secondary rather than the root cause.

The user-facing symptom is not a visible desktop-app crash: the app window remains open but cannot complete the login/startup flow.

Start with the bundled codex.exe app-server entry point and reproduce the immediate 0xC0000005 exit using both stdio and --listen ws://127.0.0.1:8765. Compare its behavior with the working CLI commands and the desktop logs showing initialization followed by EPIPE or websocket closure, then review related issues #45435 and #46644. Done means the app-server stays running and the desktop app completes login without repeated restarts.