New "bug" is driving me crazy...

Hi guys.

I'm having this problem with every tree since I updated to 5.6:


Notice the black line to the left of the first tree (the one on right)? It's the wood of the middle tree in the back. The branches do not even cast shadows anymore, they've gone completely transparent like that. If I add fog, sunshafts or anything that'd be blocked by them, it just goes right through them and the tree branches gain the color of my fog. This is so weird and annoying, I've not found anything regarding this issue.

Anyone else experiencing this? How can I fix it? I make level designs for my YouTube channel on Unity primarily, but because of this issue I can't even make any. :/

Any help is appreciated, thanks.

 

I noticed something new. This seems to only happen with Terrain trees.
Nevermind, the fog messes up trees placed by hand, but also the terrain ones. The only thing hand-placed trees don't do is displaying that black line. Shadows still not being cast by leaves.