Hi there, a very annoying problem appeared and need some help. I’m making an archviz exterior scene and one mesh “roof” is not showing the texture right. It’s showing like solid color.
The material on the roof should look like the wall below.
This is the picture of the UV map. It looks right but something apparently is very wrong.
I’m going crazy 
What could be the problem?
It might be a late response but try to apply scale of your objects in your 3d program. Also, there should be an option in FBX to export tangents, which works only when the mesh is tris or quads based. Be sure your 3d program has units calibrated to suit the UE4 metrics.
Very late to the party here, but in my case this issue was caused by having a bad UV scale in my texture. I had created a master material that allowed for customizable scaling in material instances but neglected to set the default scale of U and V to 1.0, so it was scaled to 0, and that made the texture just a color.
