yes of course it does not work now anymore, last night there was a dns-resolving problem, not a site-error like now.
I think -only in my oppinion- they switched off the webpage (maybe killed the process or anything equal) and work on a solution for the dns-problems of last night.
But - in my mind - it is a no-go to just reply with a 500 error instead of displaying "work in progress due to security reasons" or anything else and i would take all my btcs of btc-arbs because they don't seem to work in a professional way...