Отличное решение:

I had the same problem as above, because I could not do anything via a terminal window (unable to resolve host) or the terminal windows was just stuck and could not edit /etc/hosts.
I resolved the problem by going to:

system > Administration > Network

> unlock the widow with your password > go to the tab Host, on the second part of the the first line ( 127.0.0.1 ) type / replace the missing host by your host name, in my case that was jp-desktop the host given during the install.

Hope this help.
All the best to you all.
JP