Hello I have customized portal but its always saying "The Webpage not Available 

The webpage at http://aps1-api-omada-

controller.tplinkcloud.com:8088/portal/ could not be loaded because net::err http response code failure"

its not the same before that when I connecting to ssid it was fast, the portal was fast but now the portal so slow and I am getting that error always. I have paid the license for my 3eaps, but the error appear to all these 3 eaps, 610 and 2 225.