Hi Brandon, sorry for the issue.
Have you used the Tile Edit mode at all? You can get an error exporting the model to an .obj if the uvs haven't been changed. If you haven't, try switching to Tile Edit mode, selecting a tileset and painting any face, then re-export your model.
Do you have any other info? A line number or a screenshot of Unity's error trace would help a lot.
Hope that helps!