[BUG] Issue: Cowork "spawn UNKNOWN" error on all new chat/project creation. (conversation ID (215474628489584))

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?

Issue: Cowork "spawn UNKNOWN" error on all new chat/project creation. Existing sessions previously worked; new sessions have never worked despite extensive troubleshooting.
Environment:
Windows 11, Lenovo ThinkPad (corporate-managed, IT-admin)
Claude Desktop fresh clean reinstall (current latest version)
WSL2 fully operational, Ubuntu 22.04 (or whichever it installed) running, version 2, set as default
Hyper-V and Virtual Machine Platform features confirmed enabled
No VHDX files present anywhere on disk
Prior installation history: dozens of orphaned Claude AppX package versions accumulated before the clean install
What was tried:
Full system reboot (multiple times)
WSL2 installation and distro provisioning (Ubuntu, running, v2)
Clean uninstall and reinstall of Claude Desktop (which lost all Cowork session history and project metadata; project files in Documents\Claude survived)
Confirmed dism enablement of Microsoft-Windows-Subsystem-Linux and VirtualMachinePlatform features
Reference: GitHub issue #41546 describes a similar pattern.
Account context: Max plan. VP of Finance at PE-backed healthcare services company, Cowork is core to daily analytical workflow. Lost significant project history in clean install; need to avoid further destructive steps.
What I need: Desktop app logs reviewed by someone with internal access to determine why VM spawn fails even with WSL2 fully provisioned, and a non-destructive path to resolution.

Claude SPAWN Error Fix.docx

What Should Happen?

Claude CoWork should start a new session when a prompt is entered in both a chat and project.

Error Messages/Logs

Something went wrong

Try sending your message again.  If it keeps happening, share feedback so we can investigate.

spawn UNKNOWN

You can restart the conversation from an earlier message.

GO BACK    TRY AGAIN

Steps to Reproduce

1. Open the Claude App
2. Select the Cowork Tab
3. Start a New chat
4. Enter a prompt (any words will do)
5. Hit Enter
6. Errors out

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Version 1.14271.0 (c8f4d8)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_