[Windows desktop] Three consecutive app exits immediately after read_thread returns successfully (26.901.4073.0)

Problem and impact

The user reports three consecutive desktop app crashes that interrupted normal work. Local desktop logs show three separate process sessions ending immediately after read_thread returns successfully for the same existing task. Please investigate this repeated stability failure and provide a fix or reliable workaround.

Environment

• Windows, x64 Microsoft Store package OpenAI.Codex
• Installed package version: 26.901.4073.0
• Incident date: 2026-09-05

Observed timeline

All times below are UTC, from local desktop logs. These are final log timestamps, not independently measured native crash timestamps.

All three reads target the same task (identifier omitted). The logs show thread/read and thread/turns/list returning with errorCode=null; the second incident also includes successful thread/items/list pagination. Each old main log ends at the successful tool-response record. The next launch uses a different desktop process/session.

The second and third sessions also contain ResizeObserver loop completed with undelivered notifications shortly before the read. This is contextual evidence, not an established cause.

Reproduction outline from observed usage

1. Ask the desktop agent to inspect an existing task using read_thread.
2. The app reads the task history and reports a successful tool response in the desktop log.
3. The user experiences the desktop app closing, interrupting work.
4. After relaunch, reading that same task is followed by the same outcome.

This is reconstructed from existing logs; no additional deliberate crash was induced. Exact task contents and read parameters have not been included or independently isolated.

Expected behavior

Reading task history should leave the desktop app running. If a history payload cannot be handled, return a recoverable tool error and preserve the active task. Please capture a durable diagnostic reason for unexpected termination.

Diagnostic limitations and related reports

No explicit fatal/crash/render-process-gone record was found in the inspected day's desktop logs. The Windows Application event query for the last day did not establish a matching Codex crash event. Therefore the exact terminating component and root cause remain unconfirmed; the repeated timing is evidence of association with read_thread, not proof of an OOM or specific exception.

Potentially related: #40300 and #35799. This report differs from #40300 because the observed RPC reads return successfully rather than thread not loaded. Oversized/image payload involvement as in #35799 has not been verified here.

Only a sanitized diagnostic summary is shared. Raw conversations, local paths, task IDs, credentials, and full logs are omitted.

Start with the desktop handling of read_thread and compare the three final successful tool-response records described in the issue. Review related reports #40300 and #35799 for relevant investigation context. Done means isolating the termination or obtaining a reliable reproduction, then preserving the app or recording a durable diagnostic reason.