To fix the issue, all you have to do is assign the texture to the TextureSample node. In your first image “capture.png” look in the bottom left corner and you’ll see a field called “Texture” next to a red box. If you click on that pulldown you can select the texture you want to apply to the material, provided the textures have been imported into your Content Browser.
I’ve found that when purchasing stuff from the UE4 marketplace, materials work out of the box, but if importing a model from Blender, or some other 3rd party, the materials will import without the textures associated, and I’ll have to do it manually.