> ## 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 3502

## ERR\_NGROK\_3502

The forward-internal action can't forward between endpoints that use different protocols. This endpoint uses `PARENTPROTO`, and the endpoint you're forwarding to uses `TARGETPROTO`.

## 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_3502)