I have a project running with Sitecore 10.2, and I tried to add a connection to my website using Sitecore Rock and Visual studio 2019, but it was displayed the following error:
That error occurs with the following input parameters:
The error can be fixed with the following solutions:
1.- Change the host name with https. For example: https://sc102new4.dev/
2.- Add the http binding in IIS to the website.
Bellow the result screenshots:
Hope that helps you.