I used the command "/fill 36 -59 485 36 -8 515 wool" and received the following message: "Cannot place blocks outside of the world". Then i moved my character to 36 -59 485 (one of the coordinades from the command i tried to use) and used the command "/fill ~ ~ ~ 36 -8 515" and it worked! The same problem occurred yesterday multiple times with different coordinades.