# Codex extension fails to start: "The extension couldn't load its resources" #37458

Description

The Codex panel fails to start after opening VSCode and shows:

Codex could not start. The extension couldn't load its resources.

Environment

• OS: Windows x64
• VSCode: 1.132.0 (commit df53daabb18cd157bdb08c7f01c34df936cf12f4)
• Extension: openai.chatgpt 26.803.41515 (win32-x64)
• Extension installed/updated: 2026-08-07

Steps to reproduce

1. Open VSCode.
2. Open the Codex sidebar or panel.
3. Wait about 30 seconds; the error "Codex couldn't load its resources." appears.

Console output (Developer Tools)

Key error lines:

index.html?id=...&extensionId=openai.chatgpt...
Loading the font 'data:font/woff2;base64,...' violates the following Content Security Policy directive: "font-src 'self' https://*.vscode-cdn.net". The action has been blocked.
...
Codex couldn't load its resources.

Troubleshooting already tried

• Developer: Reload Window
• Fully quit and restart VSCode
• Uninstall and reinstall the Codex extension
• Cleared %APPDATA%\Code\Service Worker\CacheStorage and ScriptCache
• Tried to roll back the extension version, but "Install Another Version..." failed with "Error while downloading VSIX: Canceled"

Additional analysis

From the extension source, initializeWebview sets a 30-second startup timeout for the webview and requires a ready message within that window. If VSCode's CSP blocks the data:font resource, the frontend may fail to initialize and trigger this error. Please confirm compatibility between 26.803.41515 and VSCode 1.132.0, and consider whether the webview's data:font should be served differently.