Okay, this is getting weird. I was playing MCPE 0.15 last year. I opened a new flat world. After a few minutes of building senseless stuff in the world, the game crashed. When i opened the world again, i can saw a monolith(?) That was sorrounding the world. Its like a terrain generation glitch. When I look at the world settings, the seed m changed into 0. Its like a whole new minecraft terrain generated in the flatworld. I have no idea how to fix this. (The glitch was probably patched in 1.1.1.1 when i tried the glitch)