> ## Documentation Index
> Fetch the complete documentation index at: https://ngrok.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Error 6506

## ERR\_NGROK\_6506

Static backend address `ADDR` is invalid (`REASON`). Use host:port as address.

## Further help

If you're having trouble resolving this error, please reach out to [support@ngrok.com](mailto:support@ngrok.com?subject=Help%20with%20ERR_NGROK_6506)
