[BUG] /mcp dialog dismisses immediately showing nothing ("MCP dialog dismissed")

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?

The /mcp slash command in Claude Code terminal opens and immediately dismisses with "MCP dialog dismissed" no servers are displayed. This previously worked and showed MCP servers.

What Should Happen?

/mcp should display a list of all configured MCP servers with their connection status, allowing management of server connections.

Error Messages/Logs

No error message. The dialog opens and immediately closes with only "MCP dialog dismissed" shown in the terminal output. No servers are displayed.

Steps to Reproduce

claude mcp list shows 18 configured servers (most connected), but /mcp shows nothing:

$ claude mcp list
claude.ai Vercel: ✓ Connected
claude.ai Canva: ✓ Connected
claude.ai Gmail: ✓ Connected
claude.ai Google Calendar: ✓ Connected
plugin:episodic-memory: ✓ Connected
plugin:pinecone: ✓ Connected
plugin:slack: ✓ Connected
n8n: ✓ Connected
brave-search: ✓ Connected
vercel: ✓ Connected
firecrawl: ✓ Connected
apify: ✓ Connected
postgres: ✓ Connected
(+ 5 more)

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

v2.1.76

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

• claude mcp list shows 18+ configured servers, most showing "✓ Connected"
• MCP tools work correctly when called (verified with live tool calls)
• MCPs are configured in ~/.claude.json global mcpServers
• Issue persists across new sessions and after laptop restart
• /mcp worked earlier in the same session (connected Slack OAuth), then stopped showing anything