ERR_NGROK_1903: The provided private key is in an unknown or unsupported format

What does ERR_NGROK_1903 mean?

ngrok returns ERR_NGROK_1903 with this message:

The provided private key is in an unknown or unsupported format.

Troubleshoot ERR_NGROK_1903 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.