Unity doesn't recognize end of edge
Hello,
I'm new to Unity and I tried making a roof of these higher buildings in blender (exported as a fbx file). As you can see in the red circle, there is this thick edge(I dont know how to call it in English), and I can't get down from there to the roof surface if I run other this in unity. I'm stuck on the same height as this edge.
If you ignore the fact that this building roof model looks completly diffrent in unity, you will notice what I mentioned above, I am stuck on the same height as the edge (Yes, I took the second photo in playing mode as you can see in the red circle). So my question is, how do I fix that? I tried searching for similar problems in Google, but I don't know how to search for that.
Thank you in advance and sorry for my bad English! Have a nice day