I can't setup a site named delta120.com? I get " Missing or invalid site address."

I am not sure if I have everything setup right. I have looked at manuals, changed config.php file, the htaccess file and checked every page to see if i can spot something that looks wrong?

I searched the knowledge database and rechecked everything? But still not working. Hopefully its something really simple?

I turned on staff access.

Appreciate the help in advance. Wolfie