What is it doing? or for that matter, not doing?
Does it not show a toolpath? rapid move?
are you using the right layer? Some drawings are in 0, some are in default, depending. If it is a multi-layer drawing, that may give you a headache as well.
I am going to assume that you are not trying to exceed the demo line limit of Sheetcam, or that you have a license and the line limit is not there.