Fresh installation - Login not working - proxy_error

[tomerl]

Hi,
I've just completed my installation of OX and tried to log in to the control panel:

http://ox.domain.com/ox6/ox.html

I first tried to login with oxadminmaster/admin_master_password and even with oxadmin/admin_password
the result is the same:
Error: 502 - Proxy Error

Why this error is showing and how can I check it?

Thanks.