Costum Tree models not showing up in game?

[Marshmalo]

I've downloaded lots of tree models and they all look fine in editer but ingame they're not showing at all exept when they take damage?

I've heard of other people having this problem aswel but cant find an explaination anywhere, anyone know why? will give rep ofc for good answer!

 

[Pharaoh_]

Mind sending the map?