[BUG] Cowork workspace fails with persistent checksum mismatch for rootfs.img.zst on macOS

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?

The Cowork workspace fails to start every session with a checksum mismatch error for rootfs.img.zst. The error persists even after deleting the vm_bundles folder — Claude re-downloads the file and the same mismatch occurs, indicating the CDN is serving a file that doesn't match the checksum baked into the app.

What Should Happen?

The workspace should download successfully and start without a checksum error.

Error Messages/Logs

Failed to start Claude's workspace — Checksum mismatch for rootfs.img.zst: expected f40e54e816c94625497b37e477a1d70fcdf980f1f0acc166b666a214083e1e00, got 0ba73900025a2576a83600eada08e1afaa0c668baa66840504fb51b907577e68

Steps to Reproduce

1. Open Claude Desktop with Cowork mode enabled
2. Workspace fails immediately with checksum mismatch error
3. Click 'reinstall workspace' in the app — error persists
4. Manually delete ~/Library/Application Support/Claude/vm_bundles
5. Reopen Claude — re-downloads rootfs.img.zst and same checksum mismatch error appears again

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Latest (Claude Desktop with Cowork)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

This appears to be server-side — the CDN is consistently serving a file with a different checksum than expected. Multiple users have reported the same issue (see #68514, #49430). The 'reinstall workspace' button does not resolve it because it does not delete the cached vm bundle files.

OS: macOS
User: carson@supio.com