ERR_NGROK_2090: The user agent filter regular expression REGEX is an invalid regular expression: ERR - ngrok documentation

What does ERR_NGROK_2090 mean?

ngrok returns ERR_NGROK_2090 with this message:

The user agent filter regular expression <REGEX> is an invalid regular expression: <ERR>.

Troubleshoot ERR_NGROK_2090 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_2090?

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