[BUG] Working MCP Server from .mcp.json causes Claude Code to exit despite no sign of issue with --debug and --mcp-debug

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 Code exits unless I delete .mcp.json

What Should Happen?

Working (or even broken) MCP servers should not cause Claude Code to exit.

Error Messages/Logs

It seems to gracefully exit

Steps to Reproduce

I have no idea.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.79

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_