[BUG] Claude Desktop 1.11187.4 (and likely 1.13576.0.0) fails to launch on Windows 11

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 1.11187.4 (and likely 1.13576.0.0) fails to launch on Windows 11 — processes run but no window appears
Installs as MSIX with SignatureKind: Developer which causes padlocked files and prevents rendering
Rolling back to 1.11187.1 via Uptodown resolves the issue completely
Avast antivirus present but not the cause (disabled, issue persisted)

There's already a related issue (#66214) but the problem extends beyond just "won't launch" to "blank screen with MSIX signature issues."

What Should Happen?

Claude Desktop should open normally as it has done for months

Error Messages/Logs

NA

Steps to Reproduce

Uninstall any previous Claude Desktop version
Download and run the latest Claude Setup.exe from claude.ai/download on Windows 11
Installer deploys as MSIX package to C:\Program Files\WindowsApps\ with SignatureKind: Developer
Launch Claude Desktop from Start menu
Claude processes appear in Task Manager (6-7 instances) but no window ever appears
App shows completely blank/white screen or no window at all
Uninstalling and reinstalling makes no difference
Disabling antivirus (Avast) makes no difference
wsreset.exe makes no difference
Re-registering the MSIX package via PowerShell makes no difference
Rolling back to version 1.11187.1 (via Uptodown archive) resolves the issue completely

Expected: Claude Desktop window opens normally after launch
Actual: Multiple Claude processes run in background, no window appears, app is completely unusable
Workaround: Install version 1.11187.1 from https://claude.en.uptodown.com/windows/versions

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

1.11187.1

Claude Code Version

1.11187.1

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

WSL (Windows Subsystem for Linux)

Additional Information

_No response_