[BUG]

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?

Cowork on Mac (Pro plan) — Browse Plugins always shows 'Failed to load marketplaces: No handler registered for eipcmessageeipc_message
eipcm​essage_CustomPlugins_$_listMarketplaces'. Tried: restarting, reinstalling workspace, deleting VM bundle, manual git clone of marketplace, uploading plugin zip. Nothing works. This has persisted for several days.

What Should Happen?

Load apps in Co work

Error Messages/Logs

Steps to Reproduce

1. Open Claude Desktop on Mac (Pro plan)
2. Go to the Cowork tab
3. Click Browse Plugins
4. Error appears: "Failed to load marketplaces: No handler registered for $eipc_message$_CustomPlugins_$_listMarketplaces"
5. Tried: restarting app, deleting VM bundle, deleting ~/.claude/plugins, git cloning marketplace manually, uploading plugin zip — none work
6. Issue has persisted for several days across multiple restarts

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

N/A — using Claude Desktop Cowork, not Claude Code CLI

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_