Your scene contains a skydome mesh with a sky material but it does not cover that part of the screen

I am trying to texture a soccer stadium and I get this message when I put a texture on a back wall of the stadium.

The inside of this wall has the texture but the back says this"

“your scene contains a skydome mesh with a sky material but it does not cover that part of the screen”

I attached a screen shot for reference. Any help would be greatly appreciated!!

THANK YOU!!