modelcontextprotocol / modelcontextprotocol/servers

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

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bug
Dominant language
TypeScript
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Description

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

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Reproduce the timeout with the affected GitHub, Postgres, or filesystem server using the stated Claude Desktop version and claude_desktop_config.json. Start from the TypeScript server handling of the logged initialize request and compare the expected response with the 60-second cancellation; done means the handshake completes for the affected servers.

Written by the indexing model from the issue text.

Assessment

Tech stack
typescript
Domain
api, backend
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Quiet
Clarity
Needs clarification
Newbie friendliness
42/100

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