I am playing the survival mode with cheats then change it to creative through cheats and make some big things and between them are the rails. Now, I am after so much time playing in the map, things goes worse. A big black hole appears just like in the other previous versions (also latest snapshots). It increases in number and destructs all my creation with a hole.
This hole is black and shows the entities at the sides. I can't cross through the hole. The hole extends till the void. Looks like its the one of the big bug in minecraft! I prevent it by making the maps backup. But this time I forget. While trying to cross it, the fps decreases from 40 to 15 or sometimes 3 to 10.