I have just created a new object on AC 9, when trying to view the object in 3D an error appears saying "Invalid 3d symbol. Open the library part for editing and check its 3d scripts for errors. " What could be wrong.
If you try to create gdl objects without learning gdl you will not go very far. What have you done, where comes the object come from? If you open the object and check the script AC should show you the inproper working command line.