Alrighty, here it is:
java.lang.NullPointerException
at Drop.bounceOff(Drop.java:50)
at Drop.act(Drop.java:36)
at greenfoot.core.Simulation.actActor(Simulation.java:568)
at greenfoot.core.Simulation.runOneLoop(Simulation.java:526)
at greenfoot.core.Simulation.runContent(Simulation.java:215)
at greenfoot.core.Simulation.run(Simulation.java:205)
I made the modification in the bounceOff from reading what the tutorial had suggested.
private void bounceOff(Actor Object) { int angleDeflect = world.getContainer().getRotation()-90; int angle = angleDeflect+90; getMovement().setDirection(angle); if(getSpeed()<0.5){ falling=false; getWorld().removeObject(this); } }