Level Design

Hi,
I am new to UE 4, I am trying to make my first level deisgn.
When I tried to put material to my level, to a single tile of landscape, it turns into black. I tried to follow the instruction on the forum saying that I need to reconfigure the Layer. But this one does not have that layer in the Paint tab of Landscape Editor.
Please help.
I also attach an image of this