What happens to the render mode (and nodes) in blender?

Question

Blender

I tried to see how the material would look like on the cube, but suddenly I noticed that the color was not applied, then I turned and twisted the scene, and in general some kind of horror began, the texture began to distort and ripple. I tried disabling material nodes and it worked. True, without nodes, you can’t configure a lot.

Blender 2.8 if what

What to do?