Chest problem

I was getting stuff out of a chest in a survival world, and when I closed the chest every entity block just disappeared. I thought it was nothing so I turned my game off then on again and opened and closed the chest, sure enough it all disappeared again. So I tried this all 3 more times with no results so I rebooted my tablet then retried. Still no results so I am reporting. Please fix this. This is my favorite world.