[BUG] Cannot still on Win11

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?

[BUG] Claude Desktop v1.1.4173 fails to launch on Windows 11 25H2 — unhandled formatjs/intl rejection

Environment

• OS: Windows 11 Pro 25H2 (Build 26200)
• Claude Desktop Version: 1.1.4173 (Squirrel/EXE installer)
• Install Path: C:\Users\micha\AppData\Local\AnthropicClaude\app-1.1.4173\
• Windows Features Enabled: Containers ✅, HypervisorPlatform ✅, Microsoft-Hyper-V-All ✅
• System Locale: en-US

What's Wrong

Claude Desktop spawns 4 background processes but never renders a window. No error dialog is shown — the app silently fails on every launch.

Error Output

Launching from PowerShell produces the following unhandled promise rejection:

(node:548) [DEP0180] DeprecationWarning: fs.Stats constructor is deprecated.
This error originated either by throwing inside of an async function without a catch block,
or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason:

Error: [@formatjs/intl] An `id` must be provided to format a message. You can either:
1. Configure your build toolchain with [babel-plugin-formatjs]
2. Configure your `eslint` config to include [eslint-plugin-formatjs]

    at nZe (..\resources\app.asar\.vite\build\index.js:83:2748)
    at Sae (..\resources\app.asar\.vite\build\index.js:83:4203)
    at WOt (..\resources\app.asar\.vite\build\index.js:705:12468)
    at RDe (..\resources\app.asar\.vite\build\index.js:705:14365)
    at Hd (..\resources\app.asar\.vite\build\index.js:705:15535)
    at EventEmitter.<anonymous> (..\resources\app.asar\.vite\build\index.js:1234:79020)

This error repeats twice (two separate unhandled rejections) on every launch attempt.

Steps to Reproduce

1. Install Claude Desktop from claude.ai/download (receives Squirrel/EXE installer, build 1.1.4173)
2. Launch Claude Desktop from Start menu or directly via PowerShell
3. App spawns 4 claude.exe processes, no window appears
4. Confirm via: Get-Process -Name *Claude* | Select Name, Id, MainWindowTitle — processes running with no MainWindowTitle

Troubleshooting Already Attempted

All of the following were attempted with no resolution:

• Clean reinstall: Uninstalled via Update.exe --uninstall, deleted %APPDATA%\Claude and %LOCALAPPDATA%\AnthropicClaude, re-downloaded and reinstalled — same error
• Reset permissions: icacls "%APPDATA%\Claude" /reset /t /q — no effect
• Cleared cache: Deleted Cache and Code Cache directories — no effect
• Created config file: Manually created empty claude_desktop_config.json ({}) in %APPDATA%\Claude — no effect
• Verified CoworkVMService: Service does not exist on this system (Stop-Service CoworkVMService returns "Cannot find any service")
• Verified Windows features: Containers, HypervisorPlatform, and Microsoft-Hyper-V-All are all enabled
• No Windows Event Viewer entries found related to Claude

Expected Behavior

Claude Desktop should launch and display the main application window.

Additional Notes

• Get-AppxPackage -Name *Claude* returns nothing — the installer deployed the Squirrel version, not the MSIX package, despite meeting all MSIX/Cowork system requirements.
• The crash appears to be a missing translation message ID in the app's internationalization layer (formatjs), causing an unhandled rejection that kills the renderer process.
• This is not a configuration, permissions, or virtualization issue — it is a bug in the application build itself.

What Should Happen?

Claude should open

Error Messages/Logs

Steps to Reproduce

Install Claude Desktop from claude.ai/download (receives Squirrel/EXE installer, build 1.1.4173)

Launch Claude Desktop from Start menu or directly via PowerShell

App spawns 4 claude.exe processes, no window appears

Confirm via: Get-Process -Name Claude | Select Name, Id, MainWindowTitle — processes running with no MainWindowTitle

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

1.1.4173

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_