Cowork sandbox crash after Pearson OnVue exam corrupts local state, Repair blocked, requires reinstall + loses routines

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?

After completing a Pearson OnVue proctored exam, Cowork became unresponsive and had to be force-closed via Task Manager "End Task." This has happened twice. On relaunch both times, the app reported it needed to be repaired (Windows Settings → Apps → Advanced options → Repair), but Repair would not complete — it appears blocked by an orphaned background process still holding a file lock. The only way to recover both times was to fully uninstall and reinstall the app.

After each reinstall, all 3 of my scheduled routines were gone from the sidebar with no export/recovery option. I had to use claude --resume in the terminal to dig through past session history and manually reconstruct the routine prompts/scripts.

What Should Happen?

Cowork's sandbox should tolerate a forced/external process kill (e.g. from third-party software closing background apps) without corrupting local app state. Repair should be able to clear its own stuck process lock rather than failing outright. Routine definitions should survive a repair/reinstall, or at minimum be exportable/backed up automatically before any repair/reinstall flow.

Error Messages/Logs

No exact error text captured at the time. Windows displayed its generic "this app needs to be repaired" prompt (Settings → Apps → Advanced options), and Repair did not complete when triggered.

Steps to Reproduce

1. Have Cowork running with active/scheduled routines in the background.
2. Launch a Pearson OnVue proctored exam session (OnVue's lockdown browser scans for and force-closes background applications as an anti-cheat measure).
3. During/after the exam, Cowork is unresponsive and must be force-closed via Task Manager "End Task."
4. Relaunch Cowork — app reports it needs Repair.
5. Attempt Repair via Settings → Apps → Installed apps → Claude → Advanced options → Repair — Repair fails to complete.
6. Only a full uninstall + reinstall restores a working app, but all previously configured routines are gone from the sidebar.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.220 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

Suspected root cause: Cowork's routines run inside a Hyper-V-backed sandbox VM (depends on vmcompute/hns/vfpext host-compute services). Pearson OnVue's lockdown browser is documented to force-terminate background applications and interfere with virtualization components during proctored exams. This looks like OnVue force-killing Cowork mid-operation rather than a clean quit, which corrupts local state.

Possibly related existing issues: #77277, #78858, #60473, #42776, #45896