OBJ import - Auto Triangulation - Error: No polygon were found on mesh ''

"When translating some geographic data into a .OBJ, and importing into UE4. More than 165 of the meshes work. Some, i am having a hard time with. I've attached an example. AUT-mesh.obj is one of the meshes i am generating. This fails. AUT-mesh-idx663.obj: trimmed to only contain the first 663 vertexes, and imports successfully AUT-mesh-idx664.obj: trimmed but fails to import (the 664 vertex causes causes the import to fail)

I tried importing the failed meshes into blender, and exporting to .OBJ, they will still fail. I tried exporting from blender as .FBX, and the import to UE4 will then work. So i might be able to use ASSIMP to convert all meshes to FBX, and that might solve the problem.... But, i thought you guys would like to see where triangulation (or whatever is needed here) isn't working when importing .OBJ."

Download attached "Meshes" (Vertices and Edges)

Import meshes, Observe that AUT-mesh and AUT-mesh-idx664.obj fail to import with "Error: No polygon were found on mesh  '' "