[BUG] Cowork fails on macOS Tahoe 26.3.1 — "Session VM process not available" when adding folder

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?

See Steps to Repro below.

Troubleshooting already attempted:

1. Deleted ~/Library/Application Support/Claude/claude-code-vm & Deleted ~/Library/Application Support/Claude/vm_bundles
2. Deleted entire ~/Library/Application Support/Claude

Full MacBook restart after each attempt. None resolved the issue

Is this a regression?
Yes — was working before today.

What Should Happen?

Local folders should mount successfully in Cowork

Error Messages/Logs

**Errors observed (in order):**
1. (earlier) RPC error: failed to mount /mnt/.virtiofs-root/shared/Users/pp/Documents/Claude as Claude: source path is not accessible: stat /mnt/.virtiofs-root/shared/Users/pp/Documents/Claude: operation not permitted
2. (now) Session VM process not available

Steps to Reproduce

Version: Claude 1.3561.0 (fbc74b) 2026-04-20T14:59:51.000Z
OS: macOS Tahoe 26.3.1, Apple Silicon

Steps

• go to Cowork
• add folder
• browse to local folder
• click open

What's Wrong?

• Error: Session VM process not available. The session may not be fully initialized.

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude 1.3561.0 (fbc74b) 2026-04-20T14:59:51.000Z

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_