Claude in Chrome: Browser extension not connected despite correct setup

Description

"Claude in Chrome" browser automation fails to connect with the error:

Browser extension is not connected. Please ensure the Claude browser extension is installed and running...

All configuration appears correct but the connection is never established.

Environment

• Claude Code: v2.1.78
• Chrome Extension: Claude in Chrome (Beta) v1.0.62
• Extension ID: fcoeoabgfenejglbffodgkkbkcdhcgfn
• OS: macOS Darwin 25.3.0
• Chrome: Running with claude.ai open and logged in

Setup Verified

• Native messaging host config exists at ~/Library/Application Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_code_browser_extension.json
• Config points to correct binary at ~/.claude/chrome/chrome-native-host
• Binary exists and is executable (wrapper script calling ~/.local/share/claude/versions/2.1.78 --chrome-native-host)
• Extension ID in config matches installed extension
• Claude Code launched with --chrome flag
• /chrome command run from CLI
• Chrome fully restarted (Cmd+Q and reopened) after native messaging host file was created
• claude.ai tab open and logged in with same account

Steps to Reproduce

1. Install Claude in Chrome extension v1.0.62
2. Launch Claude Code with claude --chrome
3. Open Chrome with claude.ai logged in
4. Call mcp__claude-in-chrome__tabs_context_mcp — returns "Browser extension is not connected"
5. Run /chrome from CLI
6. Fully restart Chrome
7. Retry — same error persists

Expected Behavior

The extension should connect and tabs_context_mcp should return tab information.