Basically what the title says... I got the shapes to work by using Triangulate Faces in Blender and exporting as OBJ, but the objects visually seem to have some form of bug in Asset Forge. I attempted to make a corner for the inward curve blocks and the faces seem to only show when viewed from one direction, making them partially invisible when attempting to work with them. See the included images.

As an update, I can export as .obj and Blender will show the faces normally if the object is opened. However, attempting to export as a sprite, I get what I see in Asset Forge. Thus, sprite exports end up unusable unless I want to show the object rendered as if some of its faces didn't exist.

Just sent the e-mail off, so you should have it soon. It will have Sylvia in the subject line.

I figured out how to fix the problem. It was the Normals for the faces... for some reason it worked fine and didn't show problems in Blender but they were actually not set or set facing the wrong way.

Fix:
It can be fixed in Blender once the shape is finished and the faces triangulated by going to Mesh -> Normals -> Recalculate Outside for anyone else having the same issue. I don't know why it needs this but it worked for the shape I made.