Geometry has no Surface Material or Texture

Hello guys,

the Problem is the following: I don´t know why but somehow all my Geometry elements are surfaceless. I can select them from the world outliner but they are invisible and when i click where the object should be nothing happens. Also in the Details tab there are no such categories as “Surface properties” or “Surface materials”. I just started using this engine so maybe i just don´t see a simple thing but i would appreciate it if you could help me. Thank you ^^

Geometry you made, or even the built-in cubes?