when you export it, type in the file name, towards the bottom there is a check box. Make sure tool path is checked. If nothing is checked it will export nothing
I asked the same question the other day. You need to check either *toolpath* or *selected* checkbox when you create the export. If you do not have a toolpath and that is checked you will get a blank file. I use the selected check box with a portion of the drawing being exported already selected with cursor. Works great.