### Preflight Checklist - [x] I have searched [existing issues](https://github.com/anthropics/claude-code/issues?q=is%3Aissue%20state%3Aopen%20label%3Abug) 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? Preflight Checklist

[BUG] Cowork VM boots successfully but API is unreachable on Windows

Resolved 💬 13 comments Opened Feb 11, 2026 by chrishadley1983 Closed Feb 22, 2026

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?

<html>
<body>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Preflight Checklist</h2>
<ul class="contains-task-list">
<li class="task-list-item"><input disabled="" type="checkbox" checked=""> I have searched existing issues and this hasn't been reported yet</li>
<li class="task-list-item"><input disabled="" type="checkbox" checked=""> This is a single bug report</li>
<li class="task-list-item"><input disabled="" type="checkbox" checked=""> I am using the latest version of Claude Code</li>
</ul>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">What's Wrong?</h2>
<p class="font-claude-response-body break-words whitespace-normal leading-[1.7]">Cowork workspace VM boots and connects to the network successfully, but the API reachability check fails with <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">PROBABLY_UNREACHABLE</code> → <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">UNREACHABLE</code>. This happens 100% of the time on the new Windows Cowork release (announced Feb 10, 2026).</p>
<p class="font-claude-response-body break-words whitespace-normal leading-[1.7]">The host machine can reach <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">api.anthropic.com:443</code> without issues — the problem is specifically inside the VM's network path.</p>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Environment</h2>
<ul class="[li_&]:mb-0 [li_&]:mt-1 [li_&]:gap-1 [&:not(:last-child)_ul]:pb-1 [&:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3">
<li class="whitespace-normal break-words pl-2"><strong>Platform:</strong> Windows 11 24H2 (Build 10.0.26200)</li>
<li class="whitespace-normal break-words pl-2"><strong>CPU:</strong> AMD Ryzen 7 PRO 5850U</li>
<li class="whitespace-normal break-words pl-2"><strong>RAM:</strong> ~30GB</li>
<li class="whitespace-normal break-words pl-2"><strong>Claude Desktop Version:</strong> 1.1.2685</li>
<li class="whitespace-normal break-words pl-2"><strong>Claude Code VM SDK:</strong> 2.1.34</li>
<li class="whitespace-normal break-words pl-2"><strong>Subscription:</strong> Max</li>
</ul>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Network Adapters (active)</h2>
<div class="overflow-x-auto w-full px-2 mb-6">
Adapter | Description
-- | --
Wi-Fi 2 | Intel Wi-Fi 6 AX200 160MHz
vEthernet (WSL (Hyper-V firewall)) | Hyper-V Virtual Ethernet Adapter
Tailscale | Tailscale Tunnel
vEthernet (cowork-vm-nat) | Hyper-V Virtual Ethernet Adapter #2

</div>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Key Log Output (<code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">cowork_vm_node.log</code>)</h2>
<div class="relative group/copy bg-bg-000/50 border-0.5 border-border-400 rounded-lg"><div class="sticky opacity-0 group-hover/copy:opacity-100 top-2 py-2 h-12 w-0 float-right"><div class="absolute right-0 h-8 px-2 items-center inline-flex z-10"><button class="inline-flex
items-center
justify-center
relative
shrink-0
can-focus
select-none
disabled:pointer-events-none
disabled:opacity-50
disabled:shadow-none
disabled:drop-shadow-none border-transparent
transition
font-base
duration-300
ease-[cubic-bezier(0.165,0.85,0.45,1)] h-8 w-8 rounded-md active:scale-95 backdrop-blur-md Button_ghost__BUAoh" type="button" aria-label="Copy to clipboard" data-state="closed"><div class="relative"><div class="transition-all opacity-100 scale-100" style="width: 20px; height: 20px; display: flex; align-items: center; justify-content: center;"><svg width="20" height="20" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg" class="transition-all opacity-100 scale-100" aria-hidden="true" style="flex-shrink: 0;"><path d="M12.5 3C13.3284 3 14 3.67157 14 4.5V6H15.5C16.3284 6 17 6.67157 17 7.5V15.5C17 16.3284 16.3284 17 15.5 17H7.5C6.67157 17 6 16.3284 6 15.5V14H4.5C3.67157 14 3 13.3284 3 12.5V4.5C3 3.67157 3.67157 3 4.5 3H12.5ZM14 12.5C14 13.3284 13.3284 14 12.5 14H7V15.5C7 15.7761 7.22386 16 7.5 16H15.5C15.7761 16 16 15.7761 16 15.5V7.5C16 7.22386 15.7761 7 15.5 7H14V12.5ZM4.5 4C4.22386 4 4 4.22386 4 4.5V12.5C4 12.7761 4.22386 13 4.5 13H12.5C12.7761 13 13 12.7761 13 12.5V4.5C13 4.22386 12.7761 4 12.5 4H4.5Z"></path></svg></div><div class="absolute inset-0 flex items-center justify-center"><div class="transition-all opacity-0 scale-50" style="width: 20px; height: 20px; display: flex; align-items: center; justify-content: center;"><svg width="20" height="20" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg" class="transition-all opacity-0 scale-50" aria-hidden="true" style="flex-shrink: 0;"><path d="M15.1883 5.10908C15.3699 4.96398 15.6346 4.96153 15.8202 5.11592C16.0056 5.27067 16.0504 5.53125 15.9403 5.73605L15.8836 5.82003L8.38354 14.8202C8.29361 14.9279 8.16242 14.9925 8.02221 14.9989C7.88203 15.0051 7.74545 14.9526 7.64622 14.8534L4.14617 11.3533L4.08172 11.2752C3.95384 11.0811 3.97542 10.817 4.14617 10.6463C4.31693 10.4755 4.58105 10.4539 4.77509 10.5818L4.85321 10.6463L7.96556 13.7586L15.1161 5.1794L15.1883 5.10908Z"></path></svg></div></div></div></button></div></div><div class="overflow-x-auto"><pre class="code-block__code !my-0 !rounded-lg !text-sm !leading-relaxed p-3.5" style="color: rgb(20, 24, 31); background: transparent; font-family: var(--font-mono);"><code style="color: rgb(20, 24, 31); background: transparent; font-family: var(--font-mono); white-space: pre-wrap;"><span><span>2026-02-11 09:55:41 [info] All files ready in C:\Users\Chris Hadley\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
</span></span><span>2026-02-11 09:55:41 [info] [VM:steps] download_and_sdk_prepare completed (352830ms)
</span><span>2026-02-11 09:55:41 [info] [VM:steps] load_swift_api completed (0ms)
</span><span>2026-02-11 09:55:41 [info] [VM:start] Configuring Windows VM service...
</span><span>2026-02-11 09:55:41 [info] [VM:start] Windows VM service configured
</span><span>2026-02-11 09:55:53 [info] [VM:start] Still waiting for guest connection... 10152ms elapsed, 14 polls
</span><span>2026-02-11 09:55:53 [info] [VM] Network status: NOT_CONNECTED
</span><span>2026-02-11 09:55:53 [info] [VM:steps] sdk_install started
</span><span>2026-02-11 09:55:54 [info] [VM] Network status: CONNECTED
</span><span>2026-02-11 09:55:58 [info] [VM:steps] sdk_install completed (4483ms)
</span><span>2026-02-11 09:55:58 [info] [VM:start] Startup complete, total time: 369633ms
</span><span>2026-02-11 09:55:59 [info] [VM] API reachability: PROBABLY_UNREACHABLE
</span><span>2026-02-11 09:56:23 [info] [VM] API reachability: UNREACHABLE
</span><span>2026-02-11 09:56:23 [warn] [VM:network] API is unreachable</span></code></pre></div></div>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Steps to Reproduce</h2>
<ol class="[li_&]:mb-0 [li_&]:mt-1 [li_&]:gap-1 [&:not(:last-child)_ul]:pb-1 [&:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-1 pl-8 mb-3">
<li class="whitespace-normal break-words pl-2">Install Claude Desktop on Windows 11 24H2 (Build 26200)</li>
<li class="whitespace-normal break-words pl-2">Sign in with a paid subscription</li>
<li class="whitespace-normal break-words pl-2">Switch to the Cowork tab</li>
<li class="whitespace-normal break-words pl-2">Workspace VM downloads, boots, and connects to network</li>
<li class="whitespace-normal break-words pl-2">API reachability check fails — workspace never becomes usable</li>
</ol>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">What Should Happen</h2>
<p class="font-claude-response-body break-words whitespace-normal leading-[1.7]">After <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">[VM] Network status: CONNECTED</code>, the API reachability check should succeed and the workspace should become usable.</p>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Troubleshooting Already Attempted</h2>
<ul class="[li_&]:mb-0 [li_&]:mt-1 [li_&]:gap-1 [&:not(:last-child)_ul]:pb-1 [&:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3">
<li class="whitespace-normal break-words pl-2">✅ Full reboot</li>
<li class="whitespace-normal break-words pl-2">✅ Deleted <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">%APPDATA%\Claude\vm_bundles</code> and let it re-download</li>
<li class="whitespace-normal break-words pl-2">✅ Cleared all Claude cache/session data (<code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">%APPDATA%\Claude\Cache</code>, <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">Code Cache</code>, <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">sessions</code>)</li>
<li class="whitespace-normal break-words pl-2">✅ Disabled Tailscale (<code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">tailscale down</code>) — no change</li>
<li class="whitespace-normal break-words pl-2">✅ Disabled IPv6 on <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">vEthernet (cowork-vm-nat)</code> — no change</li>
<li class="whitespace-normal break-words pl-2">✅ Temporarily disabled Windows Firewall (all profiles) — no change</li>
<li class="whitespace-normal break-words pl-2">✅ Verified no proxy configured (<code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">netsh winhttp show proxy</code> → Direct access)</li>
<li class="whitespace-normal break-words pl-2">✅ Verified no <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">ANTHROPIC_API_KEY</code> env var set</li>
<li class="whitespace-normal break-words pl-2">✅ Confirmed host can reach API: <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">Test-NetConnection api.anthropic.com -Port 443</code> → <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">TcpTestSucceeded: True</code></li>
<li class="whitespace-normal break-words pl-2">✅ Firewall rules for Claude exist (Inbound + Outbound Allow)</li>
<li class="whitespace-normal break-words pl-2">✅ Extensions blocklist is empty</li>
<li class="whitespace-normal break-words pl-2">✅ Only one OAuth account configured (no multi-account conflict)</li>
</ul>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Additional Context</h2>
<ul class="[li_&]:mb-0 [li_&]:mt-1 [li_&]:gap-1 [&:not(:last-child)_ul]:pb-1 [&:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3">
<li class="whitespace-normal break-words pl-2">This is a fresh Windows Cowork setup — Cowork has never worked on this machine</li>
<li class="whitespace-normal break-words pl-2">Regular Claude Desktop chat works perfectly</li>
<li class="whitespace-normal break-words pl-2">Claude Code CLI works perfectly on this machine</li>
<li class="whitespace-normal break-words pl-2">The <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">cowork-vm-nat</code> Hyper-V adapter is created successfully</li>
<li class="whitespace-normal break-words pl-2">The VM network reports <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">CONNECTED</code> before API reachability fails, suggesting the issue is in the VM's outbound routing to <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">api.anthropic.com</code> specifically, possibly through the internal proxy</li>
<li class="whitespace-normal break-words pl-2">Similar to #18854 (macOS internal proxy blocking API) but on Windows</li></ul>
</body>
</html>

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

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_

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