I've got a render bug on a TGD, when I press render it gives me an error message (see attachment) and then says finished render, 0 triangles.
I have other problems with this tgd too. If I click on either of my populations in the objects window, it freezes, and if I select the render tab, then it performs an illegal operation and closes.
In order to render I had to open the properties of the render node from the node view and proceed from there.
The two populations in this file are the free XFrog Pine and Sweet Birch trees.
BTW> great work on TG2, it's an amazingly flexible piece of kit.