Can not get into one specific world

Minecraft does not let me get into one world for some reason. I tried restarting my iPad, clicking the world many times, and getting really mad, but it stops at "generating world" when it gets to full loaded xp bar. I also created a copy of it, but that didn't work. I ended up deleting the world and making a new one. I started playing it, then left to go shopping. When I got back the same issue was happening on the new world. I have no idea why this is happening, and I need help.