So I just ran into another strange issue with the T4 Beta, deleting all Object Populations causing application to crash. I added 4 populations to my scene but could not get them to render, even though they appeared to be sitting on the terrain, so I decided to delete them and try saving the heightfield as a .ter file loading it in TerraConv and resave the terrain then reload it and try it again but the application would crash if I tried to delete 2 populations in a row. To successfully delete the populations I had to delete 1 then save, delete 2nd, crash, reopen project, delete next, save, delete 2nd, crash, reopen project, delete next, save, reopen project, delete last population, save.
Whew, a lot of work to delete 4 populations, 1 of the populations was pretty big but not sure if that should effect deleting it.
Going to try again loading one project with the .ter saved from within T4 Beta and another using the .ter file that was loaded and saved with TerraConv.