[BUG] Cowork slash commands return "Unknown skill" — affects custom org plugin skills AND built-in /feedback

[inespicarro]

Preflight Checklist

• I have searched existing issues and this hasn't been reported yet
• This is a single bug report (please file separate reports for different bugs)
• I am using the latest version of Claude Code

What's Wrong?

After renaming a skill folder in our org plugin from daily-brief to daily-brief-tungsten (repo: Tungsten-Automation-AI-Office/Claude-Plugins, plugin name: org-skills), Cowork's slash command resolver returns "Unknown command" for both my custom skill and Anthropic's /feedback. Both commands appear in the / autocomplete dropdown with their correct descriptions — but invocation fails immediately. Reproducible across ~50 Tungsten Automation users, persists across full app restarts, marketplace.json version bumps (1.0.0 → 1.0.2), and rename. Natural-language triggering of the same skills works correctly.

What Should Happen?

Typing /org-skills:daily-brief-tungsten should invoke the skill that the autocomplete dropdown advertises. Typing /feedback should open Anthropic's built-in feedback flow. The resolver should match what autocomplete shows.

Error Messages/Logs

Unknown command: /org-skills:daily-brief-tungsten
Unknown skill: feedback.

Steps to Reproduce

In an org plugin marketplace, rename a skill folder (e.g. daily-brief → daily-brief-tungsten)
Update SKILL.md frontmatter name: to match new folder
Bump marketplace.json version
Commit and push (auto-syncs to Cowork per our admin)
Restart Cowork fully (close from system tray, reopen)
Type / — autocomplete shows the renamed skill with correct description
Select it or type /org-skills:daily-brief-tungsten — observe "Unknown command"
Try /feedback — observe "Unknown skill: feedback."
Try natural language ("give me my daily brief") — works correctly

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

N/A — first time attempting a skill folder rename

Claude Code Version

Not applicable — I'm using Cowork desktop app, not Claude Code CLI. Cowork version: latest available (auto-updated).

Platform

Other

Operating System

Windows

Terminal/Shell

Other

Additional Information

Plugin: org-skills v1.0.2 in marketplace tungsten-automation-claude-plugins

Repo: github.com/Tungsten-Automation-AI-Office/Claude-Plugins

Affected users: ~50 Tungsten Automation employees

Workaround: natural-language triggering ("give me my daily brief")

The fact that Anthropic's own /feedback also returns "Unknown skill" suggests this isn't just a rename edge case — the entire skill registry resolver appears broken in affected Cowork instances

[github-actions]

Found 3 possible duplicate issues:

1. Plugin skills discoverable but not invocable via Skill tool #46079
2. [BUG] Skill loads into context and works via the internal Skill tool, but /skill-name and /plugin:skill slash commands return "Unknown skill" #37956
3. [BUG] Marketplace plugins fail to load skills in Cowork -- zip upload of same plugin works fine #39400

This issue will be automatically closed as a duplicate in 3 days.

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🤖 Generated with Claude Code

[inespicarro]

Thanks for surfacing related issues. Reviewing the three:

#46079 (Plugin skills discoverable but not invocable via Skill tool) is the closest symptom match — autocomplete shows the skill with full description, but invocation returns "Unknown command".
#37956 was closed as duplicate of #42471 ("fixed in Claude Code 2.1.98"), but I'm reproducing on the latest available Cowork desktop build (Windows). Either the fix isn't bundled into current Cowork, or it doesn't cover the Cowork variant of the resolver.
#39400 (Cowork marketplace plugin loading) is related, but in my case the skills do load — autocomplete and natural-language triggering both work cleanly. Only the slash-command resolver fails.

Additional Cowork-specific evidence that may not be in the other threads:

Anthropic's own built-in /feedback command returns "Unknown skill: feedback" on the same install — so the broken resolver is system-wide, not plugin-specific.
Reproduces consistently across ~50 Tungsten Automation users on the latest Cowork desktop.
Skill tool invocation (e.g. Skill("org-skills:daily-brief-tungsten") via a separate Claude session) also returns "Unknown skill" — same failure mode, confirming it's in the registry resolution layer, not the slash-command UI.

Happy to close as duplicate of #46079 if maintainers prefer — flagging this comment specifically because the "fixed in 2.1.98" status on the parent thread may need revisiting for Cowork.

Adding 👎 to the auto-closure to keep visible.

[github-actions]

Closing for now — inactive for too long. Please open a new issue if this is still relevant.

[github-actions]

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.