MCP servers timeout on initialize with Claude Desktop 1.7196.0.0 (protocol 2025-11-25)

[Mjosuex85]

Describe the bug
All MCP servers fail to connect with Claude Desktop 1.7196.0.0 (Microsoft Store).
The client sends an initialize request with protocolVersion: 2025-11-25 but times
out after 60 seconds. Servers start and connect successfully but the handshake never completes.
This worked correctly on previous versions of Claude Desktop.

To Reproduce

1. Install Claude Desktop 1.7196.0.0 from Microsoft Store
2. Configure any MCP server in claude_desktop_config.json (github, postgres, filesystem)
3. Start Claude Desktop
4. Wait ~60 seconds → "Could not attach to MCP server" error appears for all servers

Expected behavior
MCP servers connect successfully as they did on previous Claude Desktop versions.

Logs
2026-05-13T17:30:47.451Z [github] [info] Server started and connected successfully
2026-05-13T17:30:47.628Z [github] [info] Message from client: {"method":"initialize","params":{"protocolVersion":"2025-11-25","capabilities":{},"clientInfo":{"name":"claude-ai","version":"0.1.0"}},"jsonrpc":"2.0","id":0}
2026-05-13T17:31:47.642Z [github] [info] Message from client: {"jsonrpc":"2.0","method":"notifications/cancelled","params":{"requestId":0,"reason":"McpError: MCP error -32001: Request timed out"}}
2026-05-13T17:31:47.643Z [github] [info] Client transport closed
2026-05-13T17:31:47.643Z [github] [info] Server transport closed (renderer released port)

Additional context

• Claude Desktop version: 1.7196.0.0 (Microsoft Store)
• OS: Windows 11
• Affected MCP servers: @modelcontextprotocol/server-github, server-postgres, server-filesystem
• Packages tested: latest versions and pinned versions (e.g. @2025.3.28) — same result
• The server process starts correctly when run manually via npx