Claude Desktop crashes on startup when additionalDirectories contains unreachable UNC paths

Description

Claude Desktop (Windows) crashes immediately on startup when project-level settings (settings.json or settings.local.json) contain additionalDirectories entries pointing to UNC paths (\server\share\...) that are unreachable.

The server is pingable but the share is inaccessible (net use returns error 67: "The network name cannot be found"). Claude crashes with repeated 'Utility' process exited with 'crashed' errors in main.log — no useful stack trace.

Reproduction

1. Create .claude/settings.json (or settings.local.json) in a project directory with:

``json
{
"permissions": {
"additionalDirectories": [
"\\10.10.0.65\c$\SomeFolder"
]
}
}
``

1. Ensure the UNC path is not accessible (server up but share unavailable)
2. Open Claude Desktop pointed at that project directory — it crashes

Fix / Workaround

Removing the UNC paths from both settings.json and settings.local.json resolves the crash.

Expected behavior

Claude should handle unreachable additionalDirectories gracefully — log a warning and continue, or timeout and skip the path.

Environment

• Windows 10 Pro 10.0.19044
• Claude Desktop version ~1.17377.1