I am having the same issue, been working on it for a few days now with support. Have not really gotten anywhere with them. Can you access it via your mobile device using the My Cloud app? That still works for me but outside my local network I cant get access with a web browser. I just got my EX2 this week so it has never worked for me.
There is another thread about this here: Cannot connect to my EX2 Ultra via mycloud.com
