The issue was that there is no instance target for "UltraScatter Grass, Plant, and Flower Objects6 IG Instances 1" (according to the DAZStudio API). I have changed the code to handle this. Can you pls test the new installer at:
https://render.otoy.com/customerdownloads/plugins/2e/e6/93/53/OctaneRender_for_DazStudio_3_7_0_37_Win64.exe
Paul