I’m new to UE and haven’t found a solution to this:
These are obviously the edges of the UV Map… what is to do 
Thx
My guess is that your normal map doesn’t have normal map compression set
Check if the polygons have the same Smoothing Group and that the smoothing groups are exported with your FBX file.
If they have the same Smoothing Group, check if the Normals are correct.
thanks! - worked