[Windows Desktop] Failed Cloud chat creation leaves the conversation stuck with no way back to Local

What version of the Codex App are you using?

• Running Windows package: 26.727.6591.0 (resolved from the active process path)
• Registered/updated package: 26.803.10989.0
• Codex CLI bundled with the app: 0.146.0-alpha.9.2

The registered package is newer than the package used by the currently running process, so an auto-update may be pending a full app restart.

What subscription do you have?

ChatGPT Pro (promotional access through the Codex for Open Source program, as reported by the user).

What platform is your computer?

• Windows 11 25H2, build 26200.8875, x64
• ASUS ROG Zephyrus G16 GU605MI
• Intel Core Ultra 9 185H
• UI locale: Chinese
• Configured model: gpt-5.6-sol
• Reasoning effort: ultra

What issue are you seeing?

A local Codex Desktop conversation can become trapped in the Cloud-chat flow after Cloud chat creation fails.

Clicking the black Cloud button in the composer produces this error:

Unable to determine project root for task

The app displays the Chinese heading “创建云端聊天时出错” (“Error creating Cloud chat”). Repeated attempts stack multiple identical error toasts.

The important problem is not only the toast: after the failed handoff, there is no visible control to cancel the Cloud flow or return the existing conversation to Local. The conversation is left in an unusable/stuck state. Typing /local is treated as ordinary text rather than offering a recovery path.

What steps can reproduce the bug?

1. Open an existing Codex Desktop conversation associated with a local project/chat.
2. Click the black Cloud button at the bottom-right of the composer to create or continue as a Cloud chat.
3. Observe the error: Unable to determine project root for task.
4. Click the Cloud button again and observe that identical error toasts stack.
5. Try to return to Local in the same conversation.
6. Observe that no visible “Cancel”, “Back to Local”, or environment selector is available; the conversation remains stuck in the failed Cloud flow.

What is the expected behavior?

If Codex cannot determine a project root:

• Cloud chat creation should fail without changing the current Local conversation state.
• The user should be returned to the working Local composer automatically.
• The UI should provide an explicit Cancel / Back to Local action.
• Repeated identical failures should be deduplicated instead of stacking toasts.
• If a project root is required, the UI should explain how to select one before enabling the Cloud action.

What is the actual behavior?

• Cloud chat creation fails with Unable to determine project root for task.
• Multiple identical error toasts can stack.
• The existing conversation has no visible route back to Local.
• The user must abandon or fully restart the app to recover.

Additional information

This was reproduced on 2026-08-13 in the Windows desktop app. The exact error text was searched in the public openai/codex issue tracker and no matching report was found.

A screenshot exists, but it is intentionally not attached because it contains unrelated conversation content. A sanitized screenshot can be provided if needed.

No source files, tests, or entry points are identified in the report. Start by tracing the Windows Desktop Cloud-chat handoff from the Cloud button and the Unable to determine project root for task error, then inspect how failed creation preserves the Local conversation state and displays repeated toasts. Done means a failed handoff leaves Local usable, offers a visible recovery action, and avoids stacking identical failures.