I tried to change the randomtickspeed of the World, but not happened anithing. (sry for bad English, but I am hungarian.) The leaves not fall, or dropp sticks, and the saplings doesn't became a tree. The dirt blocks is cannot became grassblock. I wrote in the chat "/gamerule randomTickSpeed 300" and i have a very good pc. The problem is not because my cpu is potato. And this is very annoying. :(