Spot and Area Lights simply don't work at all

In my scene, I simply add a spot light or area light, and nothing happens. No lighting in the editor or play scene. If I add a directional light or point light, everything works just fine. I've tried everything I can think of to get the spot and area light working. I went into Edit > Project Settings > Quality then increased the amount of Pixel Light Count. I changed the Render Mode to important. I don't know what to do!