ERR_NGROK_4452: The email address being verified, EMAIL, belongs to another user

What does ERR_NGROK_4452 mean?

ngrok returns ERR_NGROK_4452 with this message:

The email address being verified, <EMAIL>, belongs to another user.

Troubleshoot ERR_NGROK_4452 with your AI agent. Connect it to the ngrok MCP server, then ask what caused the error and how to fix it.

Email support@ngrok.com and include the error code.