Black Splodges on SpeedTree with UE4 4.15.3

Hi,

I uploaded a bought Model from SpreedTree Store in UE4 4.15.3 standard ThirdPersonTemplate and
selected movable (dynamic) lighting for the tree. I don’t get rid of these black leaves, which is really
annoying!!! I already read something in forums about materials which need to be setup, which I don’t
understand and why is this necessary: they sell expensive trees and market them as drop in ready -
I expect them to look ok out of the box. by the way: a UE4 Material is imported and setup without
error-message, seems ok for me.

Any help would be highly appreciated!!!

Kindest regards
Ricky