Loading the .blend file ... no difference. The warning now boils down to error VE76: cannot load fbx file. VE268 does not appear now. I can't find an obvious reason, but there is some flaw in the structure.
Summarizing some errors I find (and I have fixed some but it seems there are more):
Many materials: try to use only one.
Lack of UV Mapping: some faces do not have mapping or material assigned.
Disconnected vertices in the middle of some edges.
Scale & Rotation not applied on objects.
I don't consider myself an expert at all. But you are skipping stages that are going to complicate things even more later on.
If I were you, I would practice a little more in modeling and research the techniques to make efficient topographies.
Also understand well how Materials and Textures work, as well as how to apply them.
Regarding Blender, you have to be sure of what you are doing (and I learned it the hard way)
And then introduce you to Trainz. And there, if you're going to pull out the hair on your head ... I still have some left.