So yeah, as I said in the downtime message, the server was hacked and crucial files were deleted from the server, which completely broke the board. Fortunately I was online as it was happening, so I was able to quickly take a backup of the database. However, there was no guarantee that the database didn't have malicious code injected into it, so I instead had to manually copy over the posts, threads, users, PMs, etc all to a fresh install. Fun times.
There might still be some bugs. I've spotted that avatars are missing, which people will just have to reupload. Any big issues, post them in here and I'll do my best to fix them.