[BUG] Plugins configured in settings.json and assigned to folder not loading in web sessions

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?

Environment
Platform: Claude Code web (not CLI)
Model: Opus 4.6
What's configured
16 plugins in ~/.claude/settings.json under enabledPlugins, all from claude-plugins-official:
frontend-design, security-guidance, claude-md-management, commit-commands, code-review, pr-review-toolkit, supabase, github, vercel, stripe, context7, agent-sdk-dev, claude-code-setup, code-simplifier, figma, feature-dev, typescript-lsp

What's assigned in UI
The same plugins are visible in the Claude Code web UI Customize panel, assigned to the project folder.

What actually loads
Only 5 skills appear in the session: update-config, simplify, loop, claude-api, session-start-hook (custom). The remaining ~12 plugins silently fail to load — no error messages.

Expected behavior
All 16 configured and folder-assigned plugins should load into the web session.

Steps to reproduce
Configure ~/.claude/settings.json with enabledPlugins listing plugins from claude-plugins-official
Assign the same plugins to a project folder via the web UI Customize panel
Start a new Claude Code web session on that project
Observe that only a subset of skills are available
Additional context
The settings.json includes extraKnownMarketplaces pointing to anthropics/claude-plugins-official. The plugins work fine on local CLI — issue is specific to web sessions.

What Should Happen?

Environment
Platform: Claude Code web (not CLI)
Model: Opus 4.6
What's configured
16 plugins in ~/.claude/settings.json under enabledPlugins, all from claude-plugins-official:
frontend-design, security-guidance, claude-md-management, commit-commands, code-review, pr-review-toolkit, supabase, github, vercel, stripe, context7, agent-sdk-dev, claude-code-setup, code-simplifier, figma, feature-dev, typescript-lsp

What's assigned in UI
The same plugins are visible in the Claude Code web UI Customize panel, assigned to the project folder.

What actually loads
Only 5 skills appear in the session: update-config, simplify, loop, claude-api, session-start-hook (custom). The remaining ~12 plugins silently fail to load — no error messages.

Expected behavior
All 16 configured and folder-assigned plugins should load into the web session.

Steps to reproduce
Configure ~/.claude/settings.json with enabledPlugins listing plugins from claude-plugins-official
Assign the same plugins to a project folder via the web UI Customize panel
Start a new Claude Code web session on that project
Observe that only a subset of skills are available
Additional context
The settings.json includes extraKnownMarketplaces pointing to anthropics/claude-plugins-official. The plugins work fine on local CLI — issue is specific to web sessions.

Error Messages/Logs

Steps to Reproduce

Configure ~/.claude/settings.json with enabledPlugins listing plugins from claude-plugins-official
Assign the same plugins to a project folder via the web UI Customize panel
Start a new Claude Code web session on that project
Observe that only a subset of skills are available
Additional context
The settings.json includes extraKnownMarketplaces pointing to anthropics/claude-plugins-official. The plugins work fine on local CLI — issue is specific to web sessions.

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude 1.1.7714 (3bd6f6) 2026-03-19T14:50:53.000Z

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Cursor

Additional Information

_No response_