Why can't I get on the HTTPS version of this site?

So after coming back to ENWorld after years of being away, I notice that this site, according to Firefox, is not giving me a secure connection. I've tried getting on the HTTPS version, but am having no success, as it does not appear to even exist -- it gives me a "cannot find the server" error. Does anyone know what may be causing this?

I don't think there is one.

Maybe someone will come along and prove me wrong.