Help with Autocad and Bryce 5

Just for a test I try to export some of my Autocad drawings of various pieces of our robot the Silver Scorpion into the 3d rendering program Bryce 5. It’s simpler than 3dsMax, so I’m using it as a kinda of “test”. It claims to be compatible, but everytime I open the file it comes out blank in Bryce. Anyone here know what I could do?:confused: