The UJ forum has been changed to a registered members only format according to the description on the home page. Looks like member registration is free so you will need to do that to view the forum. With the current cultural dynamics it's neither surprising to see the change nor unusual as most everything requires a signing up.
This.
Brad is quite protective of his site and the members who populate it. He eventually grew uncomfortable with anyone and everyone being able to read most of the site (there had been one protected forum). To read it now one must join.