[BUG] Cowork: "Failed to start Claude's workspace" — VM service not running, persists after reboot

[stevenut63]

Preflight Checklist

• I have searched existing issues and this hasn't been reported yet
• This is a single bug report (please file separate reports for different bugs)
• I am using the latest version of Claude Code

What's Wrong?

aWhen opening Cowork in Claude Desktop, the workspace fails to start with the following error:

"Failed to start Claude's workspace — VM service not running. The service failed to start."

The error persists even after rebooting the computer. The Cowork UI still loads (the prompt input and model selector are visible), but the workspace VM cannot start, making Cowork completely unusable.

This appears related to the ongoing MCP/Cowork regression introduced in Claude Desktop v1.1.3189 (build 2026-02-14), which has also broken mcp-registry and Claude in Chrome MCP connections (see issue #27492).

What Should Happen?

aThe Cowork workspace VM should start successfully when Cowork is opened. The service should be running reliably and not require workarounds to start.

Error Messages/Logs

Error shown in Cowork UI:
"Failed to start Claude's workspace
VM service not running. The service failed to start.
Restarting Claude or your computer sometimes resolves this. If it persists, you can reinstall the workspace or share your debug logs to help us improve."

Note: Error persists after full computer reboot.

Steps to Reproduce

a1. Open Claude Desktop (latest version)
2. Click on Cowork mode
3. 3. Observe the error banner: "Failed to start Claude's workspace — VM service not running. The service failed to start."
4. 4. Reboot the computer
5. 5. Re-open Claude Desktop and switch to Cowork
6. 6. Error banner appears again — the issue persists after reboot

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

No response

Claude Code Version

Latest (post-1.1.3189)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

This issue is related to the ongoing Cowork/MCP regression introduced in Claude Desktop v1.1.3189 (Feb 13-14, 2026). See also issue #27492 which documents mcp-registry and Claude in Chrome MCP connection failures in Cowork.

The error message shown in Cowork reads:

• "Failed to start Claude's workspace"
• • "VM service not running. The service failed to start."
• • • The UI suggests restarting or reinstalling the workspace, but the error persists after a full computer reboot.
      Screenshot of the error attached below.

[github-actions]

Found 3 possible duplicate issues:

1. [BUG] [macOS] Cowork VM rootfs.img download silently fails — "Download already in progress" deadlock prevents workspace from starting #26743
2. [BUG] Failed to start claude workspace w/ MacOS Sequoia 15.7.3 #24699
3. [BUG] Cowork unresponsive — LocalAgentModeSessions.start fails validation on every session attempt (macOS 15.6.1) #25177

This issue will be automatically closed as a duplicate in 3 days.

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🤖 Generated with Claude Code

[Abhi-Prad]

Getting the same issue!

[althsimon]

same here.. with windows 11

[hackerjaeger]

Same here for about 2 days; Windows 10 Pro -- all three of my computers.

What's been tried:
-full uninstall of Claude Code & desktop
-confirm virtualization set in BIOS/UEFI
-updated & validated WSL2 install
-reinstall Claude Code (no issues found with "claude doctor" command
-reinstall Claude desktop with no errors
-cleared Claude VM caches; Claude restart; full windows restart

Bottom Line: "creating claude workspace" either fails with error "Failed to Start Claude Workspace ... EBADF: bad file descriptor, rename ..." it stops at 80% and returns to main Claude Desktop screen with no errors

[minapanagiotoy-source]

same issue

[tsvitko]

same

[aditbaco]

same issue. havent been able to test it since got the cowork. its really a shame

[jpsala]

same here

[LionHuang]

same here, all ready update to Claude 1.1.4498 (24f768)

[ArtemisAI]

Experiencing the same issue on Windows 11 Pro (Build 26200), Intel Xeon E5-2680 v4, 192 GB RAM, Claude Desktop v1.1.4498. The VM downloads all bundle files successfully (rootfs.vhdx, vmlinuz, initrd) but silently crashes after 'All files ready' — never reaches 'Configuring Windows VM service'. All Hyper-V features/services are healthy. Tried: full reinstall, VM bundle wipe, vmcompute restart, registry cleanup, multiple reboots. Nothing works. Please prioritize a fix.

[juniormayhe]

go to services.msc and start Claude service for checking if it works

[Geforce3]

Getting the same issue as well from Claude:

The key error is still:

signature verification initialization failed: failed to get service executable path: The system cannot find the path specified.

This is an MSIX packaging issue — the service can't find its own path because MSIX apps run in a virtualized filesystem and Windows services don't have access to it. This is a fundamental incompatibility between how Windows services work and how MSIX packages work.

[sofiane3106]

Same issue here.

Environment:

• Windows 11 Pro 24H2 (Build 26200)
• Claude Desktop v1.1.4498.0 (MSIX)
• Lenovo ThinkPad, Intel CPU (16 cores, 40GB RAM)
• Hyper-V fully enabled, VT-x enabled in BIOS
• WSL2 running fine via HCS

Symptoms:

• Cowork shows "VM service not running. The service failed to start."
• CoworkVMService starts then immediately stops
• System event log: "Le service Claude s'est arrêté avec l'erreur spécifique au service suivante : Fonction incorrecte." (The Claude service stopped with the following service-specific error: Incorrect function.)

Key log entries from cowork_vm_node.log:

[cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
[startVM] VM not supported (win32/x64), skipping
[Callbacks] Swift VM addon not available for callbacks

What I've tried (all failed):

• Reinstalled Claude Desktop
• Restarted PC multiple times
• Enabled Hyper-V, HypervisorPlatform, VirtualMachinePlatform
• Confirmed VT-x enabled in BIOS
• Deleted vm_bundles and claude-code-vm directories
• Manually started CoworkVMService (starts then crashes immediately)

Confirmed working:

• hcsdiag list shows WSL VM running
• Get-VMHost returns valid config
• vmcompute and vmms services running
• Hyper-V infrastructure is fully functional

The issue appears to be that Claude Desktop flags yukonSilver as "unsupported" on this configuration despite all virtualization prerequisites being met.