Roxy, thank you for all of your help. I don't know what is going on, if I put your .stl in Slic3r, I can generate gcode. If I put your .scad in OpenSCAD, then export .stl, then go to Slic3r, it generates gcode fine.

HOWEVER, if I change the values at all to customize them in OpenSCAD, then export .stl, then I cannot generate code in Slic3r.

I would like to figure out why this is happening!

But what I actually need each little box needs to be 8.5mmx8.5mm square on the inside. The height needs to be 33mm. The total width of the thing must be around 158mm, so that should be 7x7 small boxes. Width of all walls 3mm should be fine.

THANK YOU!