[BUG]

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?

Confirming this same failure loop on the latest desktop version, 1.30096.5.0 (x64, non-ARM installer from claude.ai/download).

Environment

• Claude Desktop 1.30096.5.0, Windows x64
• OS: <WINDOWS VERSION — from winver on the affected machine>
• App had worked normally on this machine for months; failures began on/around 2026-08-16/17, shortly after the app updated to 1.30096.x

Symptom progression (all steps reproduced)

1. First symptom: every agent/subagent spawn crashed the app. Normal chat worked fine.
2. Service check at that point: Get-Service *cowork*, vmcompute, hns showed CoworkVMService = Stopped, while hns and vmcompute were both Running.
3. Start-Service CoworkVMService from an elevated PowerShell failed both attempts:

Cannot start service CoworkVMService on computer '.' (OpenError / CouldNotStartService — no more specific error surfaced).

1. Windows then began prompting "go to Advanced Options → Repair" for the app. Repair reported success once, the app failed again immediately, and subsequent Repair attempts reported (in yellow text) that it could not fix the issue. App Reset did not resolve it either.
2. Uninstalled and attempted reinstall. First reinstall attempt failed with:

Installation failed: AddPackage failed: AddPackage failed with HRESULT 0x80073CF6
followed by a dialog: "Administrator access is required to install Claude with full features. You can try again or install without Cowork." Diagnostic log was saved to %LOCALAPPDATA%\Temp\ClaudeSetup.log.

1. Recovery that worked (temporarily): Get-AppxPackage *claude* | Remove-AppxPackage in elevated PowerShell to clear leftover package remnants → full computer restart → ran the installer via Run as administrator. Install succeeded, previous sessions were found, and a test agent spawn worked.
2. Within the same day, the failure returned in a worse form: the app now closes instantly on launch, and clicking the app icon brings back the Windows "Advanced Options → Repair" prompt — i.e., the full loop described in this issue, now including total inability to open the app.

Notes

• Restarting the app, ending it via Task Manager, and fully rebooting the machine never helped at any stage.
• Disk ~75% free; RAM not exhausted.
• Reinstall is only a temporary fix here, matching the original report — the corruption recurs after normal use.
• Workaround in use: the Claude Code CLI (native installer, v2.1.233) runs agents on the same machine without issue, since it doesn't use the Cowork VM service.

Happy to provide the ClaudeSetup.log, Event Viewer extracts, or to test a candidate fix.

---
_Generated by Claude Code_

What Should Happen?

Spawning an agent/subagent should run without crashing the desktop app, the app should keep opening normally, and Windows Repair should either work or not be needed.

Instead, the Cowork VM service (CoworkVMService) corrupts itself: agent spawns crash the app, then the app stops opening at all, Repair fails, and reinstalling only fixes it temporarily before the loop starts again.

This is NOT resolved. The desktop app on this machine is still unusable. The only workaround found is abandoning the desktop app on that machine entirely: the Claude Code CLI (native installer, v2.1.233) runs agents on the same computer with no issues, since it does not use the Cowork VM service. To keep working with a normal setup I had to configure a second computer. This appears to be the same failure loop as #85199, still present on the latest version 1.30096.5.0.

Error Messages/Logs

CoworkVMService found Stopped while the Windows services under it were Running:
  Get-Service *cowork*, vmcompute, hns
  -> Stopped  CoworkVMService  Claude
     Running  hns              Host Network Service
     Running  vmcompute        Hyper-V Host Compute Service

Start-Service from elevated PowerShell failed (two attempts, identical):
  Start-Service : Service 'Claude (CoworkVMService)' cannot be started due to the following error: Cannot start service CoworkVMService on computer '.'.
  CategoryInfo: OpenError (System.ServiceProcess.ServiceController) ServiceCommandException
  FullyQualifiedErrorId: CouldNotStartService,Microsoft.PowerShell.Commands.StartServiceCommand

Windows app Repair: reported success once, app failed again immediately; further Repair attempts reported (yellow text) that it could not fix the issue. Reset did not help either.

Reinstall attempt then failed with:
  Installation failed: AddPackage failed: AddPackage failed with HRESULT 0x80073CF6
followed by a dialog: "Administrator access is required to install Claude with full features. You can try again or install without Cowork."
Diagnostic log was saved to %LOCALAPPDATA%\Temp\ClaudeSetup.log (attached).

Steps to Reproduce

On Windows x64 with Claude Desktop 1.30096.5.0 (had worked normally for months; failures began on/around 2026-08-16/17, shortly after the app updated to 1.30096.x):

1. Use the desktop app normally. At some point CoworkVMService stops and cannot be restarted (see logs above). From then on, every agent/subagent spawn crashes the app; normal chat still works.
2. Windows begins prompting "Advanced Options -> Repair" for the app. Repair works at most once, then reports it cannot fix the issue. Reset does not help. Restarting the app, killing it via Task Manager, and fully rebooting the machine never helped at any stage.
3. Uninstall + reinstall initially fails with AddPackage HRESULT 0x80073CF6 until leftover package remnants are removed:

Get-AppxPackage claude | Remove-AppxPackage (elevated), then full restart, then run the installer via "Run as administrator".

1. After that, install succeeds, previous sessions are found, and a test agent works — but within the same day the failure returns in a worse form: the app closes instantly on launch and the Repair prompt loop resumes. Reinstall is only ever a temporary fix; the corruption recurs after normal use.

Impact: the desktop app is effectively permanently unusable on this machine. Workaround: the Claude Code CLI (v2.1.233, native installer) runs agents on the same machine without any issues — which points at the Cowork VM service layer specifically. I had to set up a second computer to keep a normal working setup.

Disk ~75% free; RAM not exhausted. Happy to provide ClaudeSetup.log, Event Viewer extracts, or to test a candidate fix.

---
_Generated by Claude Code_

Claude Model

Other

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Unknown — desktop app auto-updated. It worked for months before breaking on/around 2026-08-16/17; broken version is 1.30096.5.0.

Claude Code Version

Desktop app 1.30096.5.0 — bundled Claude Code version unknown (app crashes before /status can be run). Standalone CLI installed on the same machine: 2.1.233 (Claude Code), which runs agents with no problems.

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_