I am trying to emboss a simple vectorized sketch I created in a .bbcd file. I have engraved this file with no problem. I saved the file with a new name, bbcd file. When I open the new file the Data-Cam Tree and drawing open normally. When I select Bobart the Emboss Model disappears from the tree. I see file ext. that can be embossed. I saved file with .stl ext. Same result. How do I get this to work?