Hi Paul, I downloaded the installer you downloaded, installed, and it worked OK. I notice that you have the correct version (1.00p), however it has not picked up that it is the demo version (see the window title on the image below with the *** DEMO *** in the header). To me, it looks like you have actually downloaded the commercial version 1.00p rather than the demo. Is it possible that you previously downloaded and installed the commercial 1.00p and the files have a newer date than the demo version so didn't install correctly? File date/sizes should be:
C:\Program Files\Smith Micro\Poser Pro 2012\Runtime\Python\addons\OctaneRender for Poser\OctanePlugin.pyc 11/02/2012 264,724 bytes
It this does not help, pls post the octaneplugin.log file from you Poser temp folder (from Edit->General Preferences->Misc) and I will investigate further.