White or gray material.

After spending hours in blender building an object and applying the textures and material, the turn gray or white in the engine after I import the object. I have followed a few vids 100% the same way they do it, but yet they still do not work. I have even dragged the material and textures into the engine and they are still white and gray. But when I apply them to a cube from the game engine, they work. They don’t work on anything I make in blender. I have done everything I can think of. Adding a sun and a backdrop in blender before rendering and still nothing. I even did the exact same thing from the unreal tutorial vids. But they still do not work. I am missing something.
Thanks.

Exporting from blender doesn’t automatically add textures into the material nodes. Using the texture files, drop them into a folder with your model ( to keep things neat). And connect the nodes into the material attributes.