I have found the culprit. A USB display adapter driver that was installed on my machine must have been interfering somehow. I have since uninstalled that application from my computer and 3d viewer appears to be working fine. If you would like to try and recreate the issue. Install http://www.displaylink.com/downloads/windows for windows 7 x64. Thank you for all your help/suggestions. On Tue, Dec 6, 2016 at 3:01 PM, Sean McFarlane