Cowork scheduled tasks fail with EXDEV on Windows when Documents folder is on a different drive

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?

When a Cowork scheduled task runs, the runtime tries to make SKILL.md available in the session by creating a hard link from the scheduled tasks folder (on D:, via OneDrive Known Folder Move) to the Claude AppData uploads folder (on C:). Hard links cannot cross drive boundaries on Windows, so the task fails immediately with EXDEV and never starts. There is no in-app error notification.

What Should Happen?

The scheduled task should start and execute normally. SKILL.md should be made available to the session via a file read rather than a hard link, which works across drives.

Error Messages/Logs

EXDEV: cross-device link not permitted, link 'D:\OneDrive\Documents\Claude\Scheduled\daily-krisp-meeting-reports\SKILL.md' -> 'C:\Users\natn\AppData\Roaming\Claude\local-agent-mode-sessions\4958f595-10a6-4fea-90a9-63b70ac155ba\6c118f84-fb65-4d25-9fd2-609633535a56\local_3f8bce9a-8f26-4aa1-b37e-32477675d08f\uploads\SKILL.md'

Steps to Reproduce

1. Enable OneDrive Known Folder Move for Documents (moves Documents folder to D:\)
2. Create any Cowork scheduled task -- Cowork stores it at D:\OneDrive\Documents\Claude\Scheduled\<task-name>\SKILL.md
3. Run the scheduled task (via Run now or wait for cron)
4. Task fails immediately with EXDEV -- session never starts

Claude Model

N/A

Is this a regression?

Yes, this worked in a previous version

Claude Code Version

Latest (Windows 11 Pro, Claude Desktop)

Platform

Windows

Operating System

Windows 11 Pro

Terminal/Shell

N/A (Claude Desktop / Cowork)

Additional Information

Root cause: Cowork uses fs.link() to make SKILL.md available in the session uploads folder. Hard links cannot span drive boundaries on Windows. This is deterministic for any user whose Documents folder is on a different drive than AppData.

This is distinct from the VHDX EXDEV issues (#27897, #25476): those use fs.rename() on the VM bundle at startup. This variant uses fs.link() on SKILL.md at task execution time, after Cowork is fully running.

Proposed fix:

• Option A (preferred): Read SKILL.md content directly from the source path rather than linking it
• Option B: EXDEV-safe fallback -- catch EXDEV from fs.link() and fall back to fs.copyFile()
• Option C: Store scheduled tasks in %APPDATA%\Claude\Scheduled\ instead of Documents\Claude\Scheduled\ (same drive as AppData)

Impact: Any user with OneDrive Known Folder Move enabled (common in enterprise Microsoft 365 deployments) cannot run scheduled tasks at all.