Why are threads not appearing

I'm looking for that one Quizmaster thread about Flagging Sudden Death quizzes. Why isn't it on the Message Board anymore?

I also can't see the original Challenges implementation thread, but I have the link which still leads to the thread. So, why ain't it here?

I would like to have these links for official Magazine purposes. @Quizmaster? Is there some secret MB Archive we don't know about?