Hi!
At first Keyshot would only display some of the objects in my Rhino scene, I then joined them with other objects in the scene and now keyshot "Fails to open...". What
What version of KeyShot are you running?
Keyshot 2.3 Pro 64 bit. Yesterday I managed to make it work but instead it neglected som other parts of the rhino file. I dont know if the objects has to be closed surfaces or open or what it is?!
Are you using "extrusions" by any chance? If so, then you will need to convert those to meshes. These extrusions don't contain tessellated information.