Most functions are not available when you are not logged into the site. You can pick the old or new skin from the bottom of the page when you are logged in if that helps.
I can even chose the skin, without being logged in.
But why do I have to change to the old skin, to get in 'recent discussions' a link to the last post?
Because it seems, that this link is everywhere else in the forum available, in both skins.
Logged in and logged out
But in the new skin, it's only available in recent discussions, if logged in.
Interesting, with the new skin, in 'recent discussion', in case someone (I) did the last post, it's marked with a ✔, no link to the last post, any longer
So I think, no log in, no chance, to get the 'last post' link in recent discussions.
It is a feature!