In VIZ 4, I cannot see some AEC objects such as walls & stairs after I import them from ADT 2005 via 3DSout or DXF. AEC Slabs come in OK as do manually extruded 3D objects. I have updated both Viz 4 and ADT 2005 with all of the latest service packs. I have also tried using VIZ 4's file linking and it says the DWG is corrupted. I have made a new ADT 2005 file with new walls and tried linking that and the DWG file was said to be corrupted. Any suggestion? Thanks in advance for your help. Mike DuLaney