If I open the TG4 Benchmark Project, all the object populations are intact and load / render properly. However, if I start a new project and insert an object / population from the Project Assets folder I receive a plethora of error messages of files not found. And the objects render out devoid of details. Somehow the internal network, even though showing the required files, has disconnected them. So I thought maybe because they were included with the Benchmark, the objects weren't reading correctly when loaded into a new project. I copied the Project Assets folder to a another folder (the free Terragen Model Pack) and tried again - and got the same thing, a list of errors. Also, I compared the node network with the Parts Shader between the Benchmark and a new project and they are completely different from each other.
As Elmer Fudd would say: "There's something scwewy going on awound here..."