Cowork: Cannot update third-party plugins — Personal tab in Browse Plugins fails to load

Description

Third-party plugins installed via "Add marketplace from GitHub" in Claude Desktop (Cowork) cannot be updated. The Personal tab in Browse plugins fails to load, making it impossible to access the update/refresh controls for personal marketplace plugins.

Steps to Reproduce

1. Install a third-party plugin from GitHub in Cowork:

• Click "+" next to prompt → Browse plugins → Personal tab → "+" → Add marketplace from GitHub
• Enter: Datarails/dr-claude-code-plugins-re
• Install the plugin (e.g., Datarails-FinanceOS v2.2.2)

1. Publish a new version to the GitHub repo (e.g., bump to v2.2.3 in marketplace.json, push, create release)
2. Attempt to update the plugin in Cowork:

• Open Browse plugins → Personal tab

Expected Behavior

• Personal tab loads showing installed personal marketplace plugins
• A "Refresh" or "Update" button is available for the marketplace
• After refresh, an "Update" button appears on the plugin with the new version

Actual Behavior

• The Personal tab in Browse plugins fails to load / is broken
• No way to trigger a marketplace refresh or plugin update
• Plugin remains stuck on the old version (2.2.2) even though 2.2.3 is published on GitHub

Workaround

Re-upload the plugin ZIP manually via Browse plugins → Upload plugin. This is not scalable for end users.

Additional Context

• Plugin: Datarails-FinanceOS (public repo)
• Claude Code CLI works fine: /plugin marketplace update + /plugin correctly detects and updates to the new version
• The issue is specific to the Cowork (Claude Desktop) UI
• Related: #26588 (SSH bug in Cowork VM also affects plugin operations)
• The plugin follows the official marketplace structure with .claude-plugin/marketplace.json and .claude-plugin/plugin.json
• Auto-update for third-party marketplaces is disabled by default in Claude Code CLI — unclear if Cowork has any auto-update support at all

Environment

• Claude Desktop (Cowork) — latest version as of 2026-03-24
• macOS
• Plugin repo: https://github.com/Datarails/dr-claude-code-plugins-re