[BUG] Adobe for Creativity plugin: Dynamic Client Registration rejected (HTTP 403)

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?

/mcp 실행 시 plugin:adobe-for-creativity:Adobe for creativity 서버가 "Needs Auth" 상태로 뜸
Authenticate 클릭 시 에러: SDK auth failed: Dynamic Client Registration rejected (HTTP 403)
재현 방법: /mcp → Adobe for creativity → Authenticate
OS: Windows 11
매번 재현됨 (Retry해도 동일한 에러)

<img width="2465" height="1528" alt="Image" src="https://github.com/user-attachments/assets/d144260d-83d1-4c6c-8215-a0a82cb07a82" />

What Should Happen?

The Adobe for Creativity plugin should authenticate successfully via OAuth, and the MCP server should connect without errors.

Error Messages/Logs

Steps to Reproduce

1. Open Claude Code and run /mcp
2. Select the "plugin:adobe-for-creativity:Adobe for creativity" MCP server (status shows "Needs Auth")
3. Click "Authenticate"
4. Error appears: "SDK auth failed: Dynamic Client Registration rejected (HTTP 403)"

Note: This happens every time, on every attempt to authenticate this plugin. OS: Windows 11.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.236 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_