Sorry, but before I misunderstand you, what exactly do you mean, "what did I change"?
First, I didn´t change anything.
I just extracted the track and started it, got same stripes on the tarmac like
@Fanapryde posted a screenshot of, got these weird shadowed walls and some more objects with weird messy vertex normals.
Then I began to fix that.
Did you upload the right version of the track?
I can redownload the track again, install it after renaming or backup old stuff and make some virgin screenshots again, from these messed up objects, if you like and needed.