Debugging a Critical Marketplace Schema Validation Failure: How One Invalid Field Blocked All Installations

At 10:16 PM ET on October 16th, 2025, a user reported they couldn't install the Claude Code Plugins marketplace. The error message was clear but devastating: ✘ Failed to add marketplace: Invalid schema: plugins.1: Unrecognized key(s) in object: 'enhances' Impact: ZERO users could install the marketplace. Complete installation failure. This is the story of how we debugged it, fixed it, added legal compliance, resolved CI/CD issues, and deployed security improvements - all in under 3 hours. The Investigation Step 1: Reproduce and Locate The first step was understanding what "plugins.1" meant. I searched the marketplace catalogs: grep -n "enhances" .claude-plugin/marketplace.json Found it: Line 59-62 in the web-to-github-issue plugin entry: "enhances": [ "web_search", "web_fetch" ] The problem? Claude Code's marketplace schema doesn't support the enhances field. This was a field I had added thinking it would be useful metadata, but the CLI rejected it completely. Step 2: The Two-Catalog P