I have a copy of my Minecraft world that was used for demonstrating stuff before I build them in my survival world (Original). But, I just wanted to delete this world, but when I press the pencil icon to edit the world, the world creation menu appears for a millisecond before automatically closing. I then tried deleting the world from the "minecraftWorlds" folder, but every time I delete the folder with the copy of the world, and restart Minecraft, the folder comes back, and pressing the folder will have a file saying "SYNC_LOCK". Opening the copy will crash the game also. I would like to hear some of the solutions you have to fix this annoying problem. Thanks!