It's DNS related,

   Domain Name: YOBIT.NET
   Registrar: REGISTRAR OF DOMAIN NAMES REG.RU LLC
   Sponsoring Registrar IANA ID: 1606
   Whois Server: whois.reg.com
   Referral URL: http://www.reg.ru
   Name Server: No nameserver

I've used their old IP address in hosts and website works well, and I was able to withdraw some coins, so it's technical problem I think

Ex.
with administrative permission edit hosts in

C:\Windows\System32\drivers\etc>

and add line

104.20.0.170   yobit.net