Hello mates
I just wanted to tell you how to solve the problem of the invisible tree.
--> You cannot set this model on a custom tree wall.
If you want to use this tree make a custom unit out of a destructible that has no Model variations, for example a barrel. Then change the "targeted as" to tree and the death sound to TreeWallDeath.
If you create a new custom unit out of an old tree wall it will not work. The modell will not be displayed in the editor. If you change the model variations to 1, then it will be visible inside the editor, but not in the game.
So create a custom unit out of a barrel or any other destructible that has only one variation and it will work i just did it.