[BUG] Cowork: 403 Request not allowed on every request — Pro plan

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?

Subject: Cowork: 403 Request not allowed on every request — Pro plan

Hi,

I'm experiencing a persistent issue with Claude Cowork: every request fails with the following error:

"Failed to authenticate. API Error: 403 Request not allowed"

Details:

• Plan: Pro
• Issue started: May 26, 2026
• Platform: Claude Desktop, Cowork tab
• Regular Claude chat works fine on the same account
• Steps taken: full reboot, re-authentication, cache cleared — issue persists

This appears to be a known bug (referenced in GitHub issues #28486, #32816, #34268), but it has not resolved on its own after more than 24 hours.

Could you please investigate and fix this for my account?

Thank you

What Should Happen?

Claude Cowork should accept requests and process them normally.

Error Messages/Logs

Failed to authenticate. API Error: 403 Request not allowed

Steps to Reproduce

1. Open Claude Desktop app (Pro subscription active)
2. Navigate to Cowork tab
3. Type any message and send
4. Error appears: "Failed to authenticate. API Error: 403 Request not allowed"

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.152 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Issue affects Claude Cowork in Desktop app, not Claude Code itself. Regular Claude chat works fine on the same account. Troubleshooting already tried: full sign-out/sign-in, app restart, system reboot, cache cleared. Related GitHub issues: #28486, #32816, #34268. Even the /feedback command in Claude Code returns 403.