[BUG] Skills are not loading to Claude Cowork on Mac

Resolved 💬 16 comments Opened Feb 16, 2026 by isardatabreeze Closed Mar 30, 2026

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?

When trying to upload new skills into Claude cowork, by dragging and dropping a .skill file into the capabilities section, inside of Claude Mac application I receive an error message saying "Internal server error".
I'm running the latest version of Claude desktop for Mac, and I tried restarting it several times, however, the error persists.
This is a critical issue as it is on the critical path of several projects. I'm working on with Claude cowork.

Just to be certain, it's not a specific skill issue, I tested older skills that previously loaded successfully to Claude on Mac, and they're generating the same error right now.

What Should Happen?

Uploading skills to the capabilities section, should make them available in Claude cowork seamlessly.

Error Messages/Logs

Steps to Reproduce

  1. Create a new skill or update an existing one
  2. Navigate to the capabilities section of the settings on Claude coworker on Mac.
  3. Drag the scale file into the relevant area.
  4. It generates an error message.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude 1.1.3189 (1b7b58) 2026-02-14T00:09:46.000Z

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

<img width="521" height="408" alt="Image" src="https://github.com/user-attachments/assets/24cde99c-3626-4563-bb2f-1129263e35d3" />

View original on GitHub ↗

16 Comments

github-actions[bot] · 4 months ago

Found 2 possible duplicate issues:

  1. https://github.com/anthropics/claude-code/issues/26131
  2. https://github.com/anthropics/claude-code/issues/24328

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

  • If your issue is a duplicate, please close it and 👍 the existing issue instead
  • To prevent auto-closure, add a comment or 👎 this comment

🤖 Generated with Claude Code

ninthspace · 4 months ago

This happened to me earlier today with claude.ai. Even the simplest skills or manually entered ones returned this error.

loganrooks · 4 months ago

Having this issue as well

OGLOCBABY · 4 months ago

yup

francisco-perez-sorrosal · 4 months ago

Same happened to me 3 hours ago

Ghostwalker245 · 4 months ago

it is still happening to me on my end, it refuses to allow me to upload a updated skill that I've recently updated.

rdelafuente · 4 months ago

Same problem here! I cannot use, replace or remove the skill. It shows Internal Server Error

raidhosn · 4 months ago

!Image

I'm getting the same issue when trying to upload a new skill, and this has been happening since yesterday. I am using a windows 11 pro

jcbt1v · 4 months ago

only able to use skills in cowork when i manually upload the .zip file into a specific chat, for anyone else stuck with this rn

francisco-perez-sorrosal · 4 months ago

Seems to be solved now. Drag and drop the skills work again and execute without problems

felixrieseberg · 4 months ago

Hi, Felix from Anthropic here. We're seeing intermittent issues and are investigating. Apologies for the trouble!

MohammedFadin · 4 months ago

Same here, Claude Cowork is not working,

jpiabrantes · 4 months ago

I am getting Claude CoWork hanging forever at launching a skill.

<img width="745" height="312" alt="Image" src="https://github.com/user-attachments/assets/0cff8d47-12ae-4657-ad23-0da6c033b692" />

oyvindhagen2 · 4 months ago

I am still experiencing the same "interal server error" issue. Skills are amazing - but only if it works!

github-actions[bot] · 3 months ago

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

github-actions[bot] · 3 months ago

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.