Codex desktop task becomes unrenderable after multi-gigabyte file-change history

Environment

• macOS
• ChatGPT desktop app, Powered by Codex & OWL
• Version 26.715.31925 (released July 17, 2026)
• Observed July 18, 2026, about 6:21-6:33 AM EDT

Description

A Codex task that had modified 19 large APFS-cloned sidecar files (about 3.1 GiB total logical size) became permanently unrenderable. Submitting a message or reopening the task repeatedly returned to a blank screen with the ChatGPT icon, followed by "Oops, an error has occurred." "Update ChatGPT" reported that this was already the latest version.

The task's underlying worker was able to finish, so the failure appears specific to serializing/parsing or rendering the task's large file-change history.

Relevant desktop log evidence

RangeError: Invalid string length
Failed to parse app-server stdout JSONL message ... lineBytes=1720880466
Failed to parse app-server stdout JSONL message ... lineBytes=3453099188
Conversation-page React error boundary ... errorMessage="Invalid string length" ... name=AppRoutes

Workaround

I created a fresh task containing only a compact handoff and archived the affected task. The fresh task renders normally.

Expected behavior

Large-file changes should be represented with bounded metadata or compact diffs. Rendering or resuming task history should never attempt to construct multi-gigabyte strings.

I can provide the three narrowly relevant timestamped desktop-log excerpts if needed. I am not posting complete logs because they contain local paths and task contents.

<img width="367" height="194" alt="Image" src="https://github.com/user-attachments/assets/546ef264-7f58-4d0b-bb89-2f35f35e3dbe" />