DXF export unable to open in Illustrator. Options?

Dear community, Our students use Sketchup for schools, and prepare work for the laser cutter as 2D DXF export files. IS there a reference work somewhere that spells out clearly what settings need to be made to ensure the files that return from the cloud are readable in Adobe Illustrator ( Current version)
MAny of the files exported by students cannot be opened in Illustrator and some can. I’m not sure what options they should be selecting. Any Ideas?

After some experimenting using Autocad 2010 works but 2013 doesn’t for the same 2D only file with exactly the same settings, possibly something wrong with the 2013 DXF interpreter.

We don’t have a dedicated lesson plan for laser cutting projects, however the Birdhouse project briefly explains which settings need to be selected to export a DWG for CNC work. The resulting export should work for both CNC and laser cutting workflows however I can’t confirm whether Illustrator will be able to open the file.

Here’s a link the the Birdhouse project in SketchUp for Schools. You can find the file export information on slide 26. Please let me know how this workflow goes!