Photons go at c, at c time dilation and length contraction are infinite. That means for photons the universe is a 2D plane, everything on their path is at a single point in this plane and they reach all points and objects on their path at the same time, not in sequence based on position.

Shadows happen when photons hit objects in sequence based on position. Clearly this is incompatible with relativity and shadows are real so relativity is wrong.

The only way to hit objects in sequence is to go slower than light but light doesn't do that.