[BUG] Windows: Cowork plugin marketplace empty — plugins.claude.ai does not resolve

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?

The Cowork plugin marketplace is completely empty when browsing — no plugins appear at all. The root cause is that plugins.claude.ai does not resolve via DNS.
Navigating to https://plugins.claude.ai in a browser also fails, and nslookup plugins.claude.ai returns no result. Other Anthropic domains (api.anthropic.com, claude.ai) resolve fine.
This appears to be the Windows equivalent of #26951.

What Should Happen?

Browsing plugins in Customize → Browse plugins should load the marketplace and display available plugins for installation.

Error Messages/Logs

# DNS verification
nslookup plugins.claude.ai
# ❌ No result / fails to resolve

nslookup claude.ai
# ✅ Resolves successfully

nslookup api.anthropic.com
# ✅ Resolves successfully

Steps to Reproduce

Open Claude Desktop on Windows
Switch to Cowork tab
Click Customize in the left sidebar
Click Browse plugins
Marketplace is empty — no plugins shown

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Latest (downloaded Feb 25, 2026)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

Workarounds Attempted

Restarted Claude Desktop — no effect
Confirmed internet connection is working (all other sites load fine)
Ran ipconfig /flushdns — no effect
Switched DNS to Google (8.8.8.8) and Cloudflare (1.1.1.1) — no effect
No WSL2 or Docker Desktop installed
No VPN running
No third-party antivirus with network filtering

Additional Information
All standard client-side DNS troubleshooting has been exhausted. This may be a server-side issue where plugins.claude.ai is not resolving globally, similar to what was reported in #26951 on macOS.