After some time editing the original map file, questioning why unity would behave like that, and bashing my head into the keyboard, River Run is finally working. Apologies to everyone who tried to DL the last one, for some reason it worked fine for me although considering how broken it was I don't know how. Anyway please enjoy!
(The plane spawners are there in case you want to replace them with whatever. If you don't need them then just disable attack planes in the vehicle switch menu.)