Setup WP 3.0 MultiSite as detailed in the WPMUDEV Manual.
I am using a SubDomain structure...Mydomain.com/munetwork/
Everything is work as a MU site, I created my first site and even received the site creation notification email to the Site Admin email.
However, when I browser the new site URL: http://mydomain.com/munetwork/testsite
I get a 404 error:
The requested URL /munetwork/testsite was not found on this server.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
I logged into my Cpanel and I do not see a subdirectory created for the new site under my
parent directory /munetwork/ or in the subdirectory /blogs.dir/ . There are zero folders or files.
The parent MU site is functioning and I can see all of the MU Super Admin interfaces in wp-admin.