User blog:Palicene/MCPE Memory Crash Bug! (Much Evil)

I am currently making a city that is in a flat world. I have made this one big building that is basically like a Hotel but BETTER! But sadly, If I'm on the MCPE App but 20+ minutes than it crashes! And whenever I get back on the world, I noticed that all of my builds and progress had been deleted!! I call this the Memory Crash Bug.

Anyone else has this evil bug? :(