The page has 12 forums total, all numbered between 0-11. Each of those forums has at least one subforum that should be populated on the forums page. Right now, 7 of the forums are greyed out and showing only the title of the forum itself (no subforums).
You can see this most clearly at the very bottom of the forum list where there are 5 forums greyed out (4 are private, 1 is public, so you should only see the 1 greyed out). The one you can see – General Discussion — has 4 subforums that should be showing on the main forums page.