When entering a previous update world, like 0.14.3, chunks that have been saved in the previous update either corrupts or has a memory leak which will crash if you enter the previously updated chunk.

Ex. I was out travelling the world during update 0.14.3 but updated the world to 0.15.0. After updating the app i continued travelling with no problems at all. But when i entered chunks that have been pre loaded from 0.14.3 the game just exits to my apps screen. I continuously enter the app and try to enter the same chunks but will crash every time. I cannot enter my house or get anywhere close to it.