cannot save my world in mcpe 1.1.0.1

hi guys, so i am phasing a problem in mcpe. so what is happning is when ever i try to save my world it crashes and it goes back to homescreen. so when i go back too the game it doesn't save and also with a duplication glich in this game like when i put stuff in my inventory it saves but the rest of the world it does't save. please pix this. thanks.