When I try to create a world using the "Water World" preset, it starts to act like it will load the world upon crating the world, but never does (the dirt background appears and says creating world, but that's as far as it gets). I have to use task manager to end the task and then reopen minecraft. The world then appears on my worlds list, but trying to play is causes the same problem. I have also tried creating the water world using a previous version of minecraft (which loaded properly) and then opening it in the snapshot, to no avail. Normal superflat worlds seem to load fine (I've loaded tunnelers dream and the default superflat with no issues, both from previously created and newly created)