Crash !!

App crashes when attempting to open achievements in world ,app crashes when the game lags, app crashes sometimes with no reason , lag happens when attempting to put 30 mobs or more and crash game , app lags when the game automatically singing in for XBOX live then app crashes , app crashes sometimes on load screen just like 0.14 but the game crashes alote on my ipad mini 1st generation ios 9.3 iphone 4s ios 9 ipad 2 ipad pro