[BUG] [Bug] Cowork RPC mount error on every conversation - virtiofs fails to mount artifact path despite directory existing

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?

Every Cowork conversation fails immediately with this RPC mount error, even on brand new conversations unrelated to the original artifact:
RPC error: failed to mount /mnt/.virtiofs-root/shared/Users/ramirj07/Documents/Claude/Artifacts/sprint-report-template as .artifacts/sprint-report-template: source path does not exist and could not be created: /mnt/.virtiofs-root/shared/Users/ramirj07/Documents/Claude/Artifacts/sprint-report-template: mkdir /mnt/.virtiofs-root/shared/Users/ramirj07/Documents: file exists

The folder ~/Documents/Claude/Artifacts/sprint-report-template exists on disk and contains an index.html file. Cowork appears to have cached this artifact path from a previous session and attempts to mount it on every new conversation, failing each time.

Steps already tried with no resolution:

Created the folder manually via mkdir -p
Cleared extended attributes with xattr -cr
Deleted and recreated the folder
Cleared ~/Library/Application Support/Claude/

Cowork is completely unusable.

What Should Happen?

Cowork should either successfully mount the artifact path, or gracefully handle a failed mount without blocking all subsequent conversations. A stale artifact path from a previous session should not prevent new, unrelated conversations from starting.

Error Messages/Logs

Something went wrong
RPC error: failed to mount /mnt/.virtiofs-root/shared/Users/ramirj07/Documents/Claude/Artifacts/sprint-report-template as .artifacts/sprint-report-template: source path does not exist and could not be created: /mnt/.virtiofs-root/shared/Users/ramirj07/Documents/Claude/Artifacts/sprint-report-template: mkdir /mnt/.virtiofs-root/shared/Users/ramirj07/Documents: file exists

Steps to Reproduce

1. Open Claude Desktop and navigate to the Cowork tab
2. Create a new conversation and generate an artifact (HTML file) saved to ~/Documents/Claude/Artifacts/sprint-report-template
3. Close or end that conversation
4. Open any new Cowork conversation — even one completely unrelated to the original artifact
5. Observe the RPC mount error appears immediately on every new conversation, referencing the old sprint-report-template path

Error persists after:

• Restarting the app
• Clearing ~/Library/Application Support/Claude/
• Recreating the folder manually
• Clearing extended attributes on the folder and all parent directories

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

1.3883.0

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_