Hi

I'm new to CNC so I'm using Cambam to create text to engrave on aluminum plate and also I'm interested in engraving a pic on the same material.
I have a dxf file that a friend made for me, from a pic I've worked. I am able to open it in Cambam, but at the moment I try to create a Gcode from it, Cambam stop working (Not responding) and I have to close it. I am using the free version 0.8.2.
To create the Gcode I select the entire graphic, then go to CAM and select "Engrave"; then right-click on Machining from the tree and select "Create Gcode". At that point nothing will happen.
Can somebodie please tell me what is that I'm missing or how to do it?
Thanks al lot.