Plex fails to configurate

Hi all,

I have My cloud Home , enable Plex ( i can see the folders in my WD) but when I am going to CONFIGURE I receive the following error

This page isn’t working

prod-4c7c3acb1301bdf.mycloud.com is currently unable to handle this request.

HTTP ERROR 502

I am missing something?

I m experiencing this for month now and I can’t find why.
Plex is on and running on my TV an Wifi-Radio but can’t be detected by Plex-Webapp or iOS_App-