[Windows] Desktop app 26.803.41515: memory leak → silent crashes, UI desyncs from backend, project threads never load

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

Desktop app 26.803.41515

What subscription do you have?

chatgpt pro

What platform is your computer?

windows

What issue are you seeing?

Since the 26.803.41515 build (released Aug 7, 2026) arrived on this machine, the Windows desktop app has become unusable for Work/project sessions: turns hang at "Thinking" forever, project threads show an infinite spinner and never render, the whole UI becomes progressively laggier, and the app eventually exits silently (no crash dialog). Evidence below shows the backend (app-server) keeps working correctly the whole time — this is a renderer/UI-process problem, preceded by OS-level memory-leak flags on both ChatGPT.exe and codex.exe.

Everything worked normally through the evening of Aug 7 (daily scheduled automations completed at 10:32Z and 11:32Z on Aug 7). Symptoms began midday Aug 8, the first day after this build was installed.

Environment
App: ChatGPT (Codex) Desktop for Windows 26.803.41515 (MSIX package 26.803.5235.0), released 2026-08-07, Microsoft Store install
Runtime/plugins: codex-primary-runtime 26.805.11740 (auto-downloaded); command-runner 0.147.0-alpha.6.5
OS: Windows 11 build 10.0.26200.8875, x64
Hardware: Surface laptop, 32 GB RAM (≈20 GB free at idle), Intel Iris Plus + NVIDIA GTX 1660 Ti Max-Q
Network: backend traffic via HTTP_PROXY/HTTPS_PROXY to a local proxy (127.0.0.1:7897). Verified healthy: fresh-start turns complete end-to-end in ~16–18 s, websocket to wss://chatgpt.com/backend-api/codex/responses connects and streams.
Timeline
Aug 6–7 (while still working): Windows Error Reporting logged RADAR_PRE_LEAK_64 (OS memory-leak detector) for ChatGPT.exe (2026-08-06 23:45 UTC, Electron 151.0.7922.71) and codex.exe (2026-08-07 00:00 UTC).
Aug 7 evening: last fully-normal day; scheduled automations completed.
Aug 8 midday onward: every Work turn in every project sticks at "Thinking"; opening any existing project thread shows an infinite spinner; app exits silently after minutes of use.
Key evidence

1. Silent UI-process death (no fault recorded). The app-server log (~/.codex/logs_2.sqlite) simply stops mid-stream at crash time (e.g., 2026-08-08 11:35:57 UTC: last rows are routine WARN/DEBUG, then nothing). Windows Application event log has no Event 1000 for these exits — process death without an access violation, consistent with memory exhaustion, not a classic crash.

1. Backend keeps working while the UI shows an infinite spinner (state desync, cf. #24287). At 2026-08-08 12:21 UTC, while the UI displayed an endless spinner for a small test thread:

resume_thread_with_history → thread_spawn → list_models all succeeded (models cache hit),
websocket connected to wss://chatgpt.com/backend-api/codex/responses and streamed response.in_progress / metadata events,
a scheduled automation turn executed to completion in the background. The renderer never displayed any of it. After an app restart, previously "stuck" turns show up as completed.

1. Repeated error during thread resume:

resume_thread_with_history:thread_spawn:list_models{refresh_strategy=online_if_uncached}:
failed to refresh available models: timeout waiting for child process to exit

1. Ruled out local causes (none changed the behavior):

Cleared bloated logs_2.sqlite (440 MB + 131 MB WAL) and stale thread-writer-locks/*.lock
Reset ~/.cache/codex-runtimes (runtime re-downloaded cleanly)
Moved 1,200+ files out of ~/.codex/generated_images
MSIX Repair and Reset of the app; Microsoft Store repaired; confirmed app is the latest available build
Verified network path end-to-end (turns complete normally right after a fresh app start)

1. Long-standing sandbox warnings (present on healthy days too, likely unrelated but noting for completeness): hide users: failed to hide current user profile dir (C:\Users\Default): SetFileAttributesW failed ... 5 (access denied) — thousands of occurrences across days; junction: failed to create C:\Users\Default\.codex\.sandbox\cwd: access denied (os error 5) — several per day.

Repro (as observed)
Launch app; first minutes behave normally (turns complete).
Use Work sessions for a few minutes, or open a large/older project thread.
UI detaches: new turns stick at "Thinking", thread views spin forever; memory grows.
App eventually exits silently. Restart temporarily restores normal behavior; degradation repeats.
Expected

Turns render as they stream; project threads open; UI process does not leak/die.

Notes

Happy to provide the logs_2.sqlite extracts, sandbox logs, and WER references on request.

What steps can reproduce the bug?

[Windows] Desktop app 26.803.41515: memory leak → silent crashes, UI desyncs from backend, project threads never load

What is the expected behavior?

_No response_

Additional information

_No response_