Problem with shadows gives shadow to whole plane

I am following the beginner tutorial for the roll a ball game and its the first video and he sets a directional light I have no problems until he changes the shadow type. on $$anonymous$$s screen the ball gets a shadow and the plane stay w$$anonymous$$te on my screen when I change the shadow type it darkens everyt$$anonymous$$ng including the whole plane I checked everyt$$anonymous$$ng and it's exactly what he did