Conversation content becomes inaccessible after task completion since Codex 5.16 update

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

5.16 (latest version)

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

After updating to Codex App 5.16 today, I started seeing a new issue that did not happen before the update.

Frequently, after a task finishes, the current conversation page becomes blank and shows an error message: "Oops, something went wrong." In the Chinese UI, it shows "糟糕，出错了".

The conversation title is still visible at the top, and the session is still listed in the left sidebar, but when I open the session, I can no longer see the previous conversation content, task output, or code modification history.

Clicking "Retry" does not restore the conversation content.

This started happening only after today's update to version 5.16.

What steps can reproduce the bug?

I do not know the exact minimal steps to reproduce this bug yet.

However, I encountered it twice tonight, and both times it happened immediately after a Codex task finished.

Observed pattern:

1. Open Codex App 5.16 on Windows.
2. Start or continue a Codex session.
3. Use GPT-5.5 with:

• Reasoning effort: High
• Speed: Standard

1. Let Codex complete a task.
2. Immediately after the task finishes, the conversation page becomes blank and shows:

• "Oops, something went wrong"
• In Chinese UI: "糟糕，出错了"

1. The session still appears in the left sidebar, but opening it only shows the error page.
2. Clicking "Retry" does not restore the previous conversation content.

This happened twice tonight, both immediately after task completion.

Feedback ID: 019e31ce-fb1f-79e0-85fa-a6783206a6ba

I do not have a minimal code snippet because this appears to be an app/session rendering or recovery issue rather than a project-specific code issue.

What is the expected behavior?

The conversation content should remain visible after a task completes.

Even if Codex encounters an internal error, the previous conversation history, task output, and code modification process should still be recoverable or viewable.

Clicking "Retry" should either reload the original session content or provide a clear recoverable error state.

Additional information

This issue did not occur before today's update. It started after updating to Codex App 5.16.

The issue happens frequently after a task finishes. The session remains visible in the sidebar, but the actual conversation content becomes inaccessible.

I attached a screenshot showing the error page.