Whatever you did may have worked, but I can assure you that naming layers 0 is not the answer.
All i can tell ya is one of the files already had 0 as a layer, i just figured out how to change the layers or i should say add a layer, it works on the sim, i am going out to my table and try to cut it. I will let you know if it really worked! lol so if 0 is not proper should it be “layer 1”?
It should be whatever the layer is named on your drawing. It might be 0 on one and 019875 on another or black, or any name assigned to it by the program that created it. The drawing program assigns random names to layers. The layer name doesn’t matter. I don’t know any clearer way to explain it.
You can make a drawing with different layers and assign names to them, but that is done in the drawing program.
You can also move lines/contours to a different layer in Sheetcam and you have to name those new layers. You might do this to use a different size lead in on smaller contours or to cut holes at a different speed and you would have to set up a different operation for each layer.