Cannot connect Xero or QuickBooks

Everytime I try and connect Xero or QuickBooks, it doesn't work. I get to the page, on both Xero and Quickbooks, to choose the company and press ok. It is then supposed to redirect me back to Business Intelligence, but everytime it comes up with page cannot be reached. I got Xero to work the first time, but haven't been able to since.

I have already cleared the cache and cookies, but that hasn't helped.