Sorry late reply! Steam does not notify me about these messages :C try putting TVTP on top of modlist. This because mod uses a custom surface, and if it is not loaded first this surface is ignored hence why you fall through world.

How do I modify the order in which my mods are loaded?

Also, it's physically spawning the vehicles below the world's mesh. I don't think that has to do with a custom surface.

In the modlist (accessed in mod menu) you can press the arrow / indicator to move things up and down until it is at the very top. Several people have reported similar issues, and it seems to be because the custom surface. As the game does not understand that it is a valid surface, even the AI lines get set under ground by some strange reason. Hopefully the fix above helps :)

I moved it as stated and it works. Thank you!

No worries, glad to hear it solved itself :)

not working for me

Have you disable ALL other mods and done a steam integrity check as a test?

ok i disabled mods not all and check integrity and its working now thanks

Glad to hear, thanks for reporting back :)