Claude in Chrome extension not connecting on Windows despite MCP server showing "connected"

Bug Description

The Claude in Chrome browser extension (v1.0.40) fails to connect to Claude Code on Windows. The MCP server shows as "connected" in Claude Code's /mcp status, but every call to tabs_context_mcp returns "Browser extension is not connected."

Steps to Reproduce

1. Install Claude in Chrome extension (v1.0.40) from the Chrome Web Store
2. Enable the extension with "On all sites" access
3. Start Claude Code CLI
4. Verify /mcp shows claude-in-chrome · connected
5. Attempt to use any mcp__claude-in-chrome__* tool (e.g., tabs_context_mcp)

Expected Behavior

tabs_context_mcp should return tab context information from the browser.

Actual Behavior

Every call returns: "Browser extension is not connected. Please ensure the Claude browser extension is installed and running."

Troubleshooting Attempted

• Restarted PC
• Restarted Chrome multiple times
• Restarted Claude Code multiple times
• Killed all Chrome processes and relaunched
• Verified extension is enabled with correct permissions
• Confirmed MCP server shows as connected in Claude Code
• Extension has "Communicate with cooperating native applications" permission

Environment

• OS: Windows 11 Pro (NT 10.0.26200.0)
• Chrome Extension: Claude in Chrome (Beta) v1.0.40
• Extension ID: fcoeoabgfenejglbffodg