Do you mean the shading? That's probably the "Surface Normal" map that gets applied when importing OBJs, find it under the Lists tab Other Maps and delete it.
UnrealEd is a great program to learn, I've been doing quick layouts in UnrealEd, exporting them as .OBJ files and then importing them into Maya to build static meshes.
used the .obj file format on later max versions (3rd party import plugin) to preserve quads, not sure if those plugins were ported to the new version...
It'll be some hidden cancerous shit in the history of one of the nodes that was once involved in creating the mesh Combine it with a cube/export to obj/sacrifice your firstborn and it should sort itself out
Heres another shot of the issue with the wireframe included. The back face is removed, however I have closed it before and it still has this issue. I can post an obj if that would help find a solution. Thanks for looking!
You're getting an FBX tokenize error with an OBJ file? That's quite strange. Try reinstalling to a new directory after uninstalling the previous one and see if this persists.
Try blocking the whole thing in with simple overlapping primitives in Max/Maya. Import the result as an .obj to zbrush and make a unified mesh from it. Then start sculpting.