Claude Desktop 0.13.37: All Node.js MCP servers fail with "write EPIPE" on Windows 11

[zhl111]

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Discussion Topic

Issue Summary:
All Node.js-based MCP servers (including official test servers) fail with "write EPIPE" error during initialization in Claude Desktop version 0.13.37 on Windows 11. Python-based servers work correctly.
Environment:

Claude Desktop Version: 0.13.37
OS: Windows 11
Node.js installed at: C:\Program Files\nodejs
Issue affects: ALL npx/Node.js based MCP servers

Reproduction Steps:

Install any Node.js MCP server (e.g., @modelcontextprotocol/server-time)
Add to claude_desktop_config.json:

json{
"mcpServers": {
"test-time": {
"command": "npx",
"args": ["-y", "@modelcontextprotocol/server-time"]
}
}
}

Restart Claude Desktop
Observe "write EPIPE" error in logs

Expected Behavior:
Server should initialize and respond to MCP protocol handshake
Actual Behavior:

Server process starts
Client sends initialization message
Immediately receives "write EPIPE" error
Process terminates

Evidence from logs (mcp.log):
2025-10-07T00:41:05.644Z [info] [test-time] Server started and connected successfully
2025-10-07T00:41:08.045Z [info] [test-time] Message from client: {"method":"initialize"...}
2025-10-07T00:41:08.049Z [error] [test-time] write EPIPE
2025-10-07T00:41:08.060Z [error] [test-time] Server disconnected
Error originates in Claude client code:
at C:\Users\on-on\AppData\Local\AnthropicClaude\app-0.13.37\resources\app.asar.vite\build\index.js:217:2601
Impact:

Cannot use any Node.js MCP servers (majority of ecosystem)
Limits MCP functionality significantly on Windows
Python servers work fine, suggesting stdio/IPC issue with Node.js processes

Tested Configurations (All Failed):

Direct npx
Via Smithery CLI
Through CMD wrapper
With environment variables

Workaround:
Currently using Python-based servers only (Windows-MCP works perfectly)
Request:
Please investigate stdio/IPC handling between Claude Desktop and Node.js child processes on Windows 11. This appears to be platform-specific.
Logs Available:
Can provide complete logs from:

mcp.log
mcp-server-*.log
mcp.log
main.log

main.log