I updated jacob1's mod and for some reason, the undo button (Ctrl + Z) doesn't work. When I press it, the last element I created goes back to when it was created, and doesn't go away like it should. (E.g., if I put water on the screen and let it fall to the ground, and then pressed Ctrl + Z, the water doesn't go away but instead goes back to the when it was created). Also, when I put a solid on the screen like wood and pressed Ctrl + Z, it completely doesn't work. If you don't understand, check it out for yourself.