It's probably just a site bug or a problem with the server. This is a new site, so I'm sure there are a few kinks to work out still, as with anything new. Anytime something like that happens, it's a good idea to contact the site administrators directly, so they know there is a problem and can fix it.

Sherrie, the tutorial IS available -- are you looking in the right place? Download of the tutorial can be found at the Tutorial Detail page, right below the tools and materials list. You must be signed in to get it.