Normal Problem in Unreal Engine I have applied scale, recalculated normals, properly unwrapped my models, but no matter what I do, when I export it, and open the model in substance painter or UE4, the normals are all messed up.

The tower is meant to be comprised of planks of wood, from the inside the planks look fine but from out side the sides go invisible. 

Is anyone else having this issue? It's only been happening since the 2.8 release.
@FFeller ur suggestion didn't work at first, turns out i was on Vertex Select not Face Select, so it wasnt recalculating my face normals.