The error essentially says that the document needs to have physical units — typically inch or cm units. EggBot Documents, formatted in pixel dimensions, are a good example of a document that does not have physical units.
Try creating a new document (for example A4 or letter size), by using File > Templates.
On the engraver issue, please follow up with us by e-mail; we’d like to do some more in depth debugging than is straightforward through the forum.
