ERR_NGROK_1642: Invalid endpoint configuration, OAuth cookie prefix PREFIX must consist of only alphanumeric characters with periods - ngrok documentation

What does ERR_NGROK_1642 mean?

ngrok returns ERR_NGROK_1642 with this message:

Invalid endpoint configuration, OAuth cookie prefix <PREFIX> must consist of only alphanumeric characters with periods.

Troubleshoot ERR_NGROK_1642 with your AI agent. Connect it to the ngrok MCP server, then ask what caused the error and how to fix it.

Where can I get more help with ERR_NGROK_1642?

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