This bug occurred in conjunction with the game breaking bug. After defeating the ender dragon I went through the new portal to try and find the end cities and when I entered the world would not load. I waited for about 5 minutes and then saved and exited the world. I immediately loaded back up and the world seemed fine. I played for a little while longer but then I was done playing so I saved in the end and left the game. I try and come back and I click on the desired world to open and it get stuck on the "generating world" loading screen and the tips and tricks will still load and cycle through but the entire bar will fill with green but will not load. I waited and tried to copy and the world and go into creative but nothing will work. This needs to be fixed ASAP.