This has happened a few times. Basically when you shoot a ball into the gumball machine, it sometimes doesn't enter the machine but stays in the wire ramp just above the machine. The first ball doesn't hinder game play and the gumball machine spits out a ball. However, the next time you load the machine, you get two balls stacked in the wire ramp and the camera locks on the gumball machine closeup view making it impossible to continue play. The gumball machine still spits out a ball, but you can't see the flippers so this is basically a game ending bug.