How to find where a Virtualmin settings is stopping websites showing?

Hi,
my websites aren’t showing and I am not sure how to search for where the error in Virtualmin’s settings could be?

After a Virtualmin rebuild I have tried:

dig www.mydomain.com

isup.me

Virtualmin > System Information

Virtualmin > System Settings > Re-Check Configuration

Virtualmin > System Settings > Virtualmin Configuration > Networking settings > Default virtual server IP address: my LAN IP > Default IP address for DNS records: Other address: my WAN IP.

Some errors I am receiving are:

Browser shows no website.

dig www.mydomain.com shows:

; <<>> DiG 9.9.2-P1 <<>> www.mydomain.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 26233 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1280 ;; QUESTION SECTION: ;www.mydomain.com. IN A

;; Query time: 29 msec ;; SERVER: 127.0.1.1#53(127.0.1.1) ;; WHEN: Mon Jul 22 08:20:44 2013 ;; MSG SIZE rcvd: 48

Webmin > Others > File Manager > home > mydomain > public_html > index.html > Preview shows error: index.html is not in a supported format. If I double click on index.html, index.html shows the webpage.

Hello, I changed the LAN IP on Virtualmin and now the DNS has error: One or more of your nameservers did not respond.
I did change IP via Virtualmin > Update Incorrect IP Addresses > Change Now. All LAN IP addresses changed, except Server Configuration > DNS Options > Allowed sender IPv4addresses…and Server Configuration > DNS Records > Record name > domain.com.