Lost setting up domains
A year ago I set up an Ubuntu 14.04 server and that has been working ok for me.
Now I try to set up an Ubuntu 16.04 server and I am completely lost. Somehow I can't set up domains.
As far as I can remember a year ago the main domain was installed automatically during setup and my second domain was easily added with Virtualmin. Now the main domain couldn't find its page - what the installation of Virtualmin somehow repaired. But nwo I get an Ubuntu default page of which I have no idea from where it comes. In the old server the domain files came under my /home directory but there is still nothing to see there.
I also tried to add another domain with Virtualmin. Bu that resulted in the error "Virtualmin is configured to setup DNS zones, but this system is not setup to use itself as a DNS server".
What am I doing wrong?