[MacOS Antigravity Latest] Codex window not opening, unresponsive on extension version update

What version of the IDE extension are you using?

26.901.22334

What subscription do you have?

Plus

Which IDE are you using?

Antigravity

What platform is your computer?

Darwin 25.6.0 arm64 arm

What issue are you seeing?

No errors, the extension just does not open.

What steps can reproduce the bug?

1. Install Antigravity IDE (latest) on macOS.
2. Install Codex extension version 26.825.51511.
3. Confirm Codex opens in the rightmost agent panel as expected.
4. Update Codex extension to 26.901.22334 (same IDE, same OS).
5. Try to open Codex in the rightmost agent panel again.
6. Observe that it no longer opens / behaves as described above.

What is the expected behavior?

Codex should continue to open in the rightmost agent panel after updating from 26.825.51511 to 26.901.22334, or at least show a clear error message instead of silently failing.

Additional information

Environment

• Codex extension version: 26.901.22334 (broken); 26.825.51511 (works)
• IDE: Antigravity IDE (latest)
• OS: macOS (Darwin 25.6.0 arm64 arm)
• Subscription: [ChatGPT Plus]
• Host type: Remote‑SSH

What I’m seeing

After updating the Codex extension from 26.825.51511 to 26.901.22334, the Codex panel no longer opens in the rightmost agent panel in Antigravity IDE, or anywhere else, even when prompted with the Command Palette.
With the older version (26.825.51511) and the same IDE version, it works as expected.

Behavior with 26.901.22334:

• The Codex entry appears in the Extensions list, but when I try to open it in the right panel, nothing happens / the panel stays blank.
• No error message.
• Downgrading to 26.825.51511 immediately restores the previous behavior.

Steps to reproduce

1. Install Antigravity IDE (latest) on macOS.
2. Install Codex extension version 26.825.51511.
3. Confirm Codex opens in the rightmost agent panel as expected.
4. Update Codex extension to 26.901.22334 (same IDE, same OS).
5. Try to open Codex in the rightmost agent panel again.
6. Observe that it no longer opens / behaves as described above.

Expected behavior

Codex should continue to open in the rightmost agent panel after updating from 26.825.51511 to 26.901.22334, or at least show a clear error message instead of silently failing.

Additional context / logs

• This matches reports of regressions in 26.901.22334 (e.g., RPC / deserialization issues when restoring chats).
• If helpful, I can provide:
  • Output from Developer: Show Running Extensions
  • Codex extension host logs (from ~/.vscode-server/data/logs/.../exthost*/openai.chatgpt/ or equivalent in Antigravity)
  • Screenshot of the right panel behavior with both versions.

Please let me know what extra diagnostics would be most useful.

Reproduce the update from Codex 26.825.51511 to 26.901.22334 in the latest Antigravity IDE on macOS with Remote-SSH. Start with Developer: Show Running Extensions and the extension-host logs under ~/.vscode-server/data/logs/.../exthost*/openai.chatgpt/. Done means the Codex panel opens again, or a clear error explains why it cannot.