Editing latest side chat message fails with "failed to edit message"

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

26.602.30954

What subscription do you have?

gpt pro

What platform is your computer?

Win 10

What issue are you seeing?

When I edit the latest message in a side chat and then click Send, the edit fails.

A popup/toast appears with the error message:

failed to edit message

The edited message is not submitted, and the original message remains unchanged.

What steps can reproduce the bug?

1. Open Codex Desktop App.
2. Open an existing thread or start a new one.
3. Use the side chat.
4. Send a message in the side chat.
5. Edit the latest message in that side chat.
6. Change the message content.
7. Click Send.

Actual result: a popup/toast says failed to edit message, and the edit is not applied.

What is the expected behavior?

After editing the latest side chat message and clicking Send, the app should submit the edited message successfully.

The side chat should continue from the updated message content.

Additional information

<img width="166" height="35" alt="Image" src="https://github.com/user-attachments/assets/230dc24d-f18e-4987-9f3e-942e458dc925" />