Copilot failing due to 5.3 Codex not being available

[sr229]

🏷️ Discussion Type

Bug

💬 Feature/Topic Area

Copilot Cloud Agent

Body

I've been trying to fix a bug using Copilot cloud agent but it keeps failing due to this specific issue

[github-actions[bot]]

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[roohan-514]

The "5.3 Codex not available" error usually means the Copilot backend is trying to route to an older Codex model that's been deprecated or temporarily down. A few things to try:

1. Switch models — In VS Code, click the Copilot icon in the bottom bar, go to Settings or Model Selection, and switch from Codex to GPT-4o or Claude 3.5 Sonnet (if available). Codex has been gradually phased out in favor of newer models.
2. Clear Copilot cache — Run these in VS Code:

• Ctrl+Shift+P → Developer: Reload Window
• If that doesn't work, delete the Copilot cache folder:
• Windows: %APPDATA%\Code\User\workspaceStorage*\GitHub.copilot*
• Mac/Linux: ~/.config/Code/User/workspaceStorage//GitHub.copilot/
  Then reload.

3. Check your Copilot status — Run Ctrl+Shift+P → GitHub Copilot: View Completions Usage or check https://github.com/settings/copilot to make sure your plan is active and not rate-limited.
4. Server-side issue — This error can also happen when GitHub's model deployment is being updated. If none of the above works, it's likely a temporary backend issue that resolves on its own within a few hours. You can check https://www.githubstatus.com/ for any ongoing incidents.
5. If it persists — File a bug report through VS Code: Help > Report Issue and select "GitHub Copilot" — include the exact error message and a screenshot. The Copilot team monitors those reports directly.