Device has blank screen return to pause menu or in game

When playing on a seed my device goes to a blank screen after 30 seconds or so the game return to pause menu (in a seed) or in the game. This happens after over 30 mins worth of play. Other times when this happens the game crashes to my tablets home screen and I have lost all progress I have done so far! Another weird issue is when i got the blank screen the items in the icons in game had vanished but could see the green bars in tools etc. Any help with this issue is much appreciated.