Now, this is my first post on an actual website design issue (yay me!).
So I’ve been playing around with WordPress MultiSite (or MultiUser, whichever) and also using my own localhost for testing purposes.  Now, it worked fine on localhost, however once it went on to the World Wide Web, things decided to not work.
So I went to the forums to see what could possibly be wrong and what the solution would be; however no one replied
After about three days of not caring any more, I decided to have a crack at it again and the solutions came straight at me.
Problem: ‘Index of /blog’
So I decided to set this site up with WPMU (it sounds better than WPMS) and use subdomains (localhost doesn’t do subdomains). Â So the first order of business was to get that configured correctly.
Luckily, the staff at Centation are brilliant and sorted the stuff out that I couldn’t, and the rest was a piece of cake (I just followed what the guide said… really easy).
Once Wildcard sub-domains was configured correctly, I was able to make new sites on sub-domains, however, I then noticed that whenever I went on to the blog page for the test site, it displayed the Index of /blog.  This wasn’t nice to see.
The Solution
I went back on to Google and did a quick search: “wordpress MU /blog index of” (notice MU, not MS), and the answer was there, waiting for me.
Wildcard Sub-domains
I had in my FileManager (I’m using cPanel) and folder called ‘blog’… so WPMU considered it as a new site (as WPMU sites are in folders in the install directory) and that is why it did not work.
The end result, make sure you don’t have folders with the same name as pages.