In my superflat world, I had been building in an older version. Then my tablet updated to the newer version automatically. I did not enable experimental gameplay, and now when I fly over to build a new creation, there is a hole where I haven't been. At first it just wasn't generating, but then when I relogged, there weren't any blocks and I could fall through. I want to have land to build on, but now I am on an island of only chunks I have generated before. I relogged again, but the holes are still there. I would put pictures, but I am afraid to play on my world now, because I don't want to generate air all around me before the bug gets fixed and I can play again.