Sometimes when me open the Minecraft.It will say sing in.so, ok I will sign in while I already do it.When l finished. I just click play button .and the world dint appears.Just have details browser and recovery world.when I click the recovery button.it say open mojang/game/world  and something.ok I do it what it say and when I open it.Just nothing in there.I think so yeah I can start new world.After few day I open Minecraft and the sign in massage come out again.So I do it again.When I m done.I click play and then the world lost again and get really upset .So I try to recovery my world again and nothing in there .I waste my time in this 'bug game'while others player dint had this issue. Why while before it dint do any problems.