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?

Preflight Checklist

• I have searched existing issues and this hasn't been reported yet
• This is a single bug report
• I am using the latest version of Claude Code

What's Wrong?

Cowork workspace VM boots and connects to the network successfully, but the API reachability check fails with PROBABLY_UNREACHABLE → UNREACHABLE. This happens 100% of the time on the new Windows Cowork release (announced Feb 10, 2026).

The host machine can reach api.anthropic.com:443 without issues — the problem is specifically inside the VM's network path.

Environment

• Platform: Windows 11 24H2 (Build 10.0.26200)
• CPU: AMD Ryzen 7 PRO 5850U
• RAM: ~30GB
• Claude Desktop Version: 1.1.2685
• Claude Code VM SDK: 2.1.34
• Subscription: Max

Network Adapters (active)

Key Log Output (cowork_vm_node.log)

2026-02-11 09:55:41 [info] All files ready in C:\Users\Chris Hadley\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
2026-02-11 09:55:41 [info] [VM:steps] download_and_sdk_prepare completed (352830ms)
2026-02-11 09:55:41 [info] [VM:steps] load_swift_api completed (0ms)
2026-02-11 09:55:41 [info] [VM:start] Configuring Windows VM service...
2026-02-11 09:55:41 [info] [VM:start] Windows VM service configured
2026-02-11 09:55:53 [info] [VM:start] Still waiting for guest connection... 10152ms elapsed, 14 polls
2026-02-11 09:55:53 [info] [VM] Network status: NOT_CONNECTED
2026-02-11 09:55:53 [info] [VM:steps] sdk_install started
2026-02-11 09:55:54 [info] [VM] Network status: CONNECTED
2026-02-11 09:55:58 [info] [VM:steps] sdk_install completed (4483ms)
2026-02-11 09:55:58 [info] [VM:start] Startup complete, total time: 369633ms
2026-02-11 09:55:59 [info] [VM] API reachability: PROBABLY_UNREACHABLE
2026-02-11 09:56:23 [info] [VM] API reachability: UNREACHABLE
2026-02-11 09:56:23 [warn] [VM:network] API is unreachable

Steps to Reproduce

1. Install Claude Desktop on Windows 11 24H2 (Build 26200)
2. Sign in with a paid subscription
3. Switch to the Cowork tab
4. Workspace VM downloads, boots, and connects to network
5. API reachability check fails — workspace never becomes usable

What Should Happen

After [VM] Network status: CONNECTED, the API reachability check should succeed and the workspace should become usable.

Troubleshooting Already Attempted

• ✅ Full reboot
• ✅ Deleted %APPDATA%\Claude\vm_bundles and let it re-download
• ✅ Cleared all Claude cache/session data (%APPDATA%\Claude\Cache, Code Cache, sessions)
• ✅ Disabled Tailscale (tailscale down) — no change
• ✅ Disabled IPv6 on vEthernet (cowork-vm-nat) — no change
• ✅ Temporarily disabled Windows Firewall (all profiles) — no change
• ✅ Verified no proxy configured (netsh winhttp show proxy → Direct access)
• ✅ Verified no ANTHROPIC_API_KEY env var set
• ✅ Confirmed host can reach API: Test-NetConnection api.anthropic.com -Port 443 → TcpTestSucceeded: True
• ✅ Firewall rules for Claude exist (Inbound + Outbound Allow)
• ✅ Extensions blocklist is empty
• ✅ Only one OAuth account configured (no multi-account conflict)

Additional Context

• This is a fresh Windows Cowork setup — Cowork has never worked on this machine
• Regular Claude Desktop chat works perfectly
• Claude Code CLI works perfectly on this machine
• The cowork-vm-nat Hyper-V adapter is created successfully
• The VM network reports CONNECTED before API reachability fails, suggesting the issue is in the VM's outbound routing to api.anthropic.com specifically, possibly through the internal proxy
• Similar to Cowork sessions fail with 'Connection error' - internal MITM proxy blocking api.anthropic.com #18854 (macOS internal proxy blocking API) but on Windows

What Should Happen?

After [VM] Network status: CONNECTED, the API reachability check should succeed and the workspace should become usable.

Error Messages/Logs

2026-02-11 09:55:41 [info] All files ready in C:\Users\Chris Hadley\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
2026-02-11 09:55:41 [info] [VM:steps] download_and_sdk_prepare completed (352830ms)
2026-02-11 09:55:41 [info] [VM:steps] load_swift_api completed (0ms)
2026-02-11 09:55:41 [info] [VM:start] Configuring Windows VM service...
2026-02-11 09:55:41 [info] [VM:start] Windows VM service configured
2026-02-11 09:55:53 [info] [VM:start] Still waiting for guest connection... 10152ms elapsed, 14 polls
2026-02-11 09:55:53 [info] [VM] Network status: NOT_CONNECTED
2026-02-11 09:55:53 [info] [VM:steps] sdk_install started
2026-02-11 09:55:54 [info] [VM] Network status: CONNECTED
2026-02-11 09:55:58 [info] [VM:steps] sdk_install completed (4483ms)
2026-02-11 09:55:58 [info] [VM:start] Startup complete, total time: 369633ms
2026-02-11 09:55:59 [info] [VM] API reachability: PROBABLY_UNREACHABLE
2026-02-11 09:56:23 [info] [VM] API reachability: UNREACHABLE
2026-02-11 09:56:23 [warn] [VM:network] API is unreachable

Steps to Reproduce

Steps to Reproduce

Install Claude Desktop on Windows 11 24H2 (Build 26200)
Sign in with a paid subscription
Switch to the Cowork tab
Workspace VM downloads, boots, and connects to network
API reachability check fails — workspace never becomes usable

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

No response

Claude Code Version

1.1.2685

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Terminal.app (macOS)

Additional Information

No response