When ever I try to load my "World1" map, I get an error saying 'Load Failed'. I have the option to 'Load backup', if I click that I then get an error message 'Load Failed, No backup found". In my Terraria folder, there are 2 "World1" save files, 'World1.wld' and 'World1.sav' What is this .sav file? All my other save worlds do not have a .sav file, they instead have a .bak file! Also, after attempting to load my backup, my .bak file is deleted! Please help!