I have one survival world that I use 90% of the time and have it built extensively. I was digging a new mine and the game crashed to my start screen on my iPad. Now when I restart the game it crashes just after building terrain. My other worlds work fine. I don't have any mods or patches, just the game as downloaded from the App Store. I was able to create a new survival world as well. I tried restarting my device but nothing seems to work. The version I have says 13.1 alpha.