Codex VS Code sidebar breaks after editing a previous message to empty and sending

What version of the IDE extension are you using?

26.506.31421

What subscription do you have?

Plus

Which IDE are you using?

VS Code

What platform is your computer?

Linux 5.15.167.4-microsoft-standard-WSL2 x86_64 x86_64

What issue are you seeing?

Summary

The Codex VS Code extension sidebar becomes unusable after editing a previous message to an empty message and sending it. After this happens, the sidebar appears to enter a corrupted state: the selected model becomes Custom, new messages cannot be sent, and the Codex process reports that it is unavailable.

The Codex CLI still works normally, so this appears to be specific to the VS Code extension/sidebar state.

Environment

• VS Code version: 1.120.0
• Codex VS Code extension version: 0.130.0
• Codex CLI: works normally
• Platform: VS Code Remote / WSL
• WSL distro: Ubuntu 24.04

Steps to reproduce

1. Open the Codex VS Code extension sidebar.
2. Start or continue a Codex chat session.
3. Edit a previous message.
4. Delete all content so the edited message is empty.
5. Send the empty edited message.
6. Observe that the Codex sidebar becomes unusable.

Expected behavior

The extension should either:

• reject the empty edited message with a validation error, or
• safely ignore it without corrupting the chat/session state.

The sidebar should remain usable, and the selected model should remain unchanged.

Actual behavior

After sending the empty edited message:

• The Codex VS Code sidebar stops working.
• The model selector changes to Custom.
• Sending new messages no longer works.
• The sidebar reports that the Codex process is unavailable.
• The issue seems limited to the affected VS Code workspace/window.
• The Codex CLI continues to work normally outside the VS Code extension.

Error message / logs

An error has occurred
Codex crashed with the following error:
Codex process errored: Codex process is not available

2026-05-14T10:53:45.823704Z WARN codex_core_plugins::manifest: ignoring interface.defaultPrompt: prompt must be at most 128 characters path=/home/howard/.codex/.tmp/plugins/plugins/build-ios-apps/.codex-plugin/plugin.json

2026-05-14T10:53:45.824083Z WARN codex_core_plugins::manifest: ignoring interface.defaultPrompt: maximum of 3 prompts is supported path=/home/howard/.codex/.tmp/plugins/plugins/plugin-eval/.codex-plugin/plugin.json

2026-05-14T10:53:45.826380Z WARN codex_core_plugins::manifest: ignoring interface.defaultPrompt: maximum of 3 prompts is supported path=/home/howard/.codex/.tmp/plugins/plugins/twilio-developer-kit/.codex-plugin/plugin.json

2026-05-14T10:53:45.826462Z WARN codex_core_plugins::manifest: ignoring interface.defaultPrompt: maximum of 3 prompts is supported path=/home/howard/.codex/.tmp/plugins/plugins/openai-developers/.codex-plugin/plugin.json

### What steps can reproduce the bug?

## Steps to reproduce

1. Open the Codex VS Code extension sidebar.
2. Start or continue a Codex chat session.
3. Edit a previous message.
4. Delete all content so the edited message is empty.
5. Send the empty edited message.
6. Observe that the Codex sidebar becomes unusable.

### What is the expected behavior?

_No response_

### Additional information

_No response_