So, since IPB 4.0 was a colossal crapfest, the forums have been reverted to 3.4. There were a few complications, but for the most part, things are fine. Some of the features that were previously available are currently missing, but they will be restored in the near future.
However, any users that registered after July 23, 2015 will no longer be in the system. In addition, posts, messages, etc that were made after July 23, 2015 are also gone, but I have a backup. If you are requiring a post to be remade, I can post it, and change the topic author. Simply make a request, and I'll do what I can.