Password Registeration Portal - Communication Error

Hi

My Name is Khaled and I work as a System Engineer for Microsoft Partner in Qatar. One of our customers needed to deploy MIM 2016 in order to let user reset their own passwords. I am assigned to do this project.

I mad a lab and have done all steps mentioned in TechNet article https://technet.microsoft.com/en-us/library/mt150255.aspx

and when I access Password Registration Portal, I receive the following error:

Please help.

Thanks.