[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?

English (לשליחה בדוח הבאג)
Summary: Cowork VM fails to connect to the API with an SSL certificate error, even after full local remediation. This appears to be a client-side bug in Claude Desktop's Cowork VM certificate handling, not a network/environment issue.
Environment:

OS: Windows 10 Pro, build 10.0.19045
Claude Desktop version: 1.22209.0 (MSIX install, Claude_1.22209.0.0_x64__pzs8sxrjxfjjc)

Timeline / symptoms:

Initially, Cowork showed: "Failed to start Claude's workspace — VM service not running."
Diagnosed that Hyper-V was not installed at all on this machine (Get-Service vmms → "Cannot find any service with service name 'vmms'").
Enabled Hyper-V via Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V -All, restarted. Confirmed both vmms and CoworkVMService now show Status: Running, StartType: Automatic.
The "VM service not running" banner disappeared — that part is resolved.
However, a second, separate error now appears a few seconds after initiating any Cowork action: "API Error: Unable to connect to API: SSL certificate verification failed. Check your proxy or corporate SSL certificates."
Regular Chat tab (non-Cowork) works normally throughout — the SSL error is exclusive to Cowork.
Ruled out network/proxy/AV interception: navigating directly to https://api.anthropic.com in Chrome returns a clean HTTP 404 (no certificate warning), confirming the TLS handshake and certificate chain are valid at the OS/browser level.
Performed a full Cowork state reset: closed all Claude processes, renamed vm_bundles, bridge-state.json, and cowork-enabled-cli-ops.json to force a clean VM rebuild. Relaunched Claude Desktop. The SSL error still occurs identically after the reset.

Conclusion: All host-level prerequisites (Hyper-V, VM service, clean network path) are confirmed correct, and a full VM/state reset did not resolve it. This matches other reported cases where the issue was confirmed to be a bug in how the Cowork VM generates/installs its internal certificate, not something fixable client-side.

What Should Happen?

<img width="505" height="510" alt="Image" src="https://github.com/user-attachments/assets/e652edd2-0de7-4841-9ab5-fae6af67c366" />

Error Messages/Logs

Steps to Reproduce

English (לשליחה בדוח הבאג)
Summary: Cowork VM fails to connect to the API with an SSL certificate error, even after full local remediation. This appears to be a client-side bug in Claude Desktop's Cowork VM certificate handling, not a network/environment issue.
Environment:

OS: Windows 10 Pro, build 10.0.19045
Claude Desktop version: 1.22209.0 (MSIX install, Claude_1.22209.0.0_x64__pzs8sxrjxfjjc)

Timeline / symptoms:

Initially, Cowork showed: "Failed to start Claude's workspace — VM service not running."
Diagnosed that Hyper-V was not installed at all on this machine (Get-Service vmms → "Cannot find any service with service name 'vmms'").
Enabled Hyper-V via Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V -All, restarted. Confirmed both vmms and CoworkVMService now show Status: Running, StartType: Automatic.
The "VM service not running" banner disappeared — that part is resolved.
However, a second, separate error now appears a few seconds after initiating any Cowork action: "API Error: Unable to connect to API: SSL certificate verification failed. Check your proxy or corporate SSL certificates."
Regular Chat tab (non-Cowork) works normally throughout — the SSL error is exclusive to Cowork.
Ruled out network/proxy/AV interception: navigating directly to https://api.anthropic.com in Chrome returns a clean HTTP 404 (no certificate warning), confirming the TLS handshake and certificate chain are valid at the OS/browser level.
Performed a full Cowork state reset: closed all Claude processes, renamed vm_bundles, bridge-state.json, and cowork-enabled-cli-ops.json to force a clean VM rebuild. Relaunched Claude Desktop. The SSL error still occurs identically after the reset.

Conclusion: All host-level prerequisites (Hyper-V, VM service, clean network path) are confirmed correct, and a full VM/state reset did not resolve it. This matches other reported cases where the issue was confirmed to be a bug in how the Cowork VM generates/installs its internal certificate, not something fixable client-side.

עברית (לידיעתכם / לתרגם אם צריך)

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

OS: Windows 10 Pro, build 10.0.19045

Claude Code Version

2.1.212

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_