Error 503 Backend fetch failed

[btrix10b]

Hello! Everytime I visit my website (http://btri.x10.bz) it says

Error 503 Backend fetch failed
Backend fetch failed
Guru Meditation:
XID: 54109982
Varnish cache server​

Please note that everytime I reload the webpage, the XID changes. My website it also hosted on the xo4 server. It happens when I view file or directory in the hosting space.
Thanks!
I received help on the IRC channel, it's working fine now