[BUG] JSON errors in Claude Cowork

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?

I am constantly getting JSON errors in the cowork desktop UI, it's unusable for me right now. Started happening yesterday https://webpagefx.mangoapps.com/msc/MjgzNTIzNV8yNDM5NDIzNQ

<img width="1857" height="1214" alt="Image" src="https://github.com/user-attachments/assets/d8e702e0-6b2b-4e04-a932-d62a31a89878" [/>[](url)](url)

What Should Happen?

I should be able to use Claude Cowork

Error Messages/Logs

API Error: JSON Parse error: Unable to parse JSON string

Steps to Reproduce

Ask Cowork anything

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

no idea

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_