I installed ClearOS on my test PC, it is a test machine, a private server, no plan for public IP address. My local LAN infrastructure has domain "home" and other subnet is "net", so new server should be "clearos.home". I cannot enter just "home" in DOMAIN field in the configuration wizard, it looks like a dot is required. So I entered ".home", it was accepted and DNS was silently broken.... ;-) After reboot, DNS was broken, Markertplace was offline, updates were not available. Disaster...

I think it is bad idea to force "dot" in domain name in the wizard form. I have found today, that "home" and "lan" domains are not recommended anymore and domain for home networks should be "home.arpa", that was declared about 2018. I run "home domain" for years and I just cannot switch my infrastructure in one day from "home" to "home.arpa"... No smart alternative for bussiness/SOHO users... :-(

I vote for removing check for "dot" in domain field form, it could be source of real trouble...
I do not understand why I have to enter "internet domain" when I selected to "private server" mode. That field is mandatory, so I entered there some nonsense...