I'm having a problem creating new subdomain subsites.
I create the site through Network Admin, it appears in the site list, the email goes out and the DB tables are created. However, when I try to access subdomain.domain1.com or /wp-admin/ I get an error saying "Could not find subdomain.domain1.com".
I currently have 3 add-on domain subsites running without problems.
So I'm not sure if it's a problem creating new subsites in general, or something specific to subdomain subsites. They worked in the past, so it shouldn't be the DNS wildcard, htaccess looks fine and I've confirmed with my host that AllowOverrides is enabled.