[BUG] Claude Desktop v1.1.4173 — Blank window on launch due to @formatjs/intl getInitialLocale error (macOS Monterey 12.6.2)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Claude Desktop (not Claude Code) launches but displays a completely blank/empty window. The UI never renders. The app was working normally before — the issue appeared after closing and reopening the app. No changes were made to the system.

The getInitialLocale function in the preload script fails with reply was never sent, which blocks the entire renderer. The @formatjs/intl library throws an unhandled error because message IDs are missing. This is NOT a Claude Code issue — it affects the Claude Desktop chat app.

A blank/empty window is displayed. The UI never renders. The app enters a zombie state after Cmd+Q.

Version: 1.1.4173
OS: macOS Monterey 12.6.2
Hardware: MacBookPro11,4 (Mid-2015, Intel)
System locale: fr-FR

What Should Happen?

Claude Desktop should launch and display the normal chat interface, falling back to English if French locale resources are unavailable.

Error Messages/Logs

**Electron verbose output:**

locale_file_path.empty() for locale fr-FR
locale resources are not loaded  (repeats 40+ times)


**main.log:**

[error] Sentry caught: {
  type: 'Error',
  value: '[@formatjs/intl] An `id` must be provided to format a message.',
  stack: undefined
}

[error] Sentry caught: {
  type: 'Error',
  value: 'reply was never sent',
  stack: 'Error: reply was never sent
    at Object.getInitialLocale (<anonymous>:21:1842)
    at <anonymous>:21:56765
    at runPreloadScript (node:electron/js2c/sandbox_bundle:2:145262)
    at executeSandboxedPreloadScripts (node:electron/js2c/sandbox_bundle:2:144535)'
}


**Direct launch output (`LANG=en_US.UTF-8 LC_ALL=en_US.UTF-8`):**

Error: [@formatjs/intl] An `id` must be provided to format a message.
    at nZe (.../app.asar/.vite/build/index.js:83:2748)
    at Sae (.../app.asar/.vite/build/index.js:83:4203)
    at WOt (.../app.asar/.vite/build/index.js:705:13101)
    at RDe (.../app.asar/.vite/build/index.js:705:14365)
    at Hd (.../app.asar/.vite/build/index.js:705:15535)
    at EventEmitter.<anonymous> (.../app.asar/.vite/build/index.js:1234:79020)

Steps to Reproduce

1. Have macOS Monterey 12.6.2 with system locale set to fr-FR
2. Launch Claude Desktop v1.1.4173
3. The app window opens but remains completely blank — no UI, no loading spinner
4. Cmd+Q closes the window but the process stays alive as a zombie in the Dock
5. Only killall -9 "Claude" terminates it

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.52 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Troubleshooting already attempted

• Full reinstall (deleted app + re-downloaded from claude.ai/download)
• Cleared all app data (~/Library/Application Support/Claude, Caches, Saved Application State)
• Rebooted the Mac
• Forced locale to en-US via defaults write and env vars (LANG, LC_ALL)
• Launched with --disable-gpu flag
• None of the above resolved the issue

Suggested fix

<img width="1440" height="830" alt="Image" src="https://github.com/user-attachments/assets/1e3fd2ee-c159-4cc9-aab4-15b525ce6a86" />

• Handle the @formatjs/intl error gracefully and fall back to en-US when locale resources are missing
• Ensure getInitialLocale always sends a reply, even on error
• Include fr-FR locale resources in the build, or map fr-FR → fr as a fallback