Changed Primary Domain for Multisite, now can't create new sites

I changed the primary domain for my multisite network and I thought everything was working, but new sites I create are not being found by the server.

I can create a new subdomain (i.e. test.Mysite.com) but when I go to the site’s dashboard I get this error message:

Server not found
Firefox can’t find the server at test.Mysite.com.