I am just transporting a villager with boat and lead to my raid farm,but I was going carefully through a nether fortress,so I just quited to menu and copied my world,that time I was sneaking and holding a lead connected to the boat with villager but what I was grabing is my bow not the lead item,and that is the last thing I did in my world,when I copied my world,both of the initial world and the copy cannot be enter! I can load them,and when I almost enter in, that world crashed,I had tried serveral times and had ported other world's level.dat to that crashed world but nothing changed.I can't upload my world it's 31MB,but I upload all files of my world and the resoucepack(i only upload the resourcepack that not just simply change some textures,textures counldn't be the problem),but the resoucepack seems not the reason of crash