Have the dedicated IP and DocumentRoot is pointing correct, its 192.185.233.181
http://artarmoncom.cityofgosford.com need to be mapped with http://artarmon.com
See screenshot for A Records: https://wpmudev.com/forums/?bb_attachments=686354&bbat=45332&inline
The domain http://artarmon.com was added as an addon domain and was having a WordPress installation on it which we removed after we installed WP MU on http://cityofgosford.com