Windows Desktop 26.908.4834.0: app-server repeatedly exits with 0xC000013A, followed by a top-level ChatGPT.exe MoAppHang

Environment

• Windows 10 Pro x64 build 19045
• OpenAI.Codex 26.908.4834.0; previous 26.903.9818.0
• ChatGPT.exe 152.0.7977.83
• Codex CLI/app-server 0.154.0-alpha.6.2

Confirmed

Two distinct failure levels are confirmed:
A. Child codex.exe app-server repeatedly exits with decimal 3221225786 = 0xC000013A = STATUS_CONTROL_C_EXIT.
B. Separately after the update, top-level ChatGPT.exe became unresponsive and Windows closed the whole desktop app.

Retained logs contain 28 app-server exits with this code: 25 before update and 3 after.

Timeline (Europe/Berlin, 2026-09-12): update registration completed 12:33:44; new ChatGPT.exe started 12:36:56; app-server exits at 12:38:09 and 12:40:53; renderer termination and Chromium GPU child gone at 12:41:28–12:41:34; Windows Application Hang Event ID 1002 at 12:41:34 with WER classification MoAppHang and hang type Top level window is idle; Windows closed ChatGPT.exe; it restarted about 20 seconds later at 12:41:54; app-server exited again at 12:44:19.

WER report ID: 2c60425c-f007-4c20-ae2d-ede5ca74235b

The evidence does not prove that A caused B. 0xC000013A is confirmed only for the child app-server; the main ChatGPT.exe event has no exception code.

Not proven

• Direct causality between 0xC000013A and ChatGPT.exe hang
• GenerateConsoleCtrlEvent, CTRL_C_EVENT, CTRL_BREAK_EVENT
• CREATE_NEW_PROCESS_GROUP, PTY/ConPTY, or taskkill as the local mechanism
• V8 OOM, GPU driver reset, WebView2 crash, access violation, or AppX corruption

Related issues

#40231 is the closest match for app-server 0xC000013A. #38444 is relevant to a possible console-control mechanism, not proven locally. #44914 and #44394 are related full-desktop/browser reports with different local signatures.

Please investigate whether 26.908.4834.0 introduced a new failure mode where backend/renderer recovery can hang or close the entire desktop shell. I can provide privacy-reviewed sanitized event and narrow log excerpts. No memory dumps or raw user-content logs are attached.

Start by comparing this report with related issues #40231, #38444, #44914, and #44394. Review the privacy-reviewed event and narrow log excerpts, including WER report 2c60425c-f007-4c20-ae2d-ede5ca74235b, while keeping the child app-server exit separate from the top-level ChatGPT.exe hang. Done means establishing whether the update introduced a reproducible recovery or desktop-shell failure and documenting a scoped next step.