Hi, Someone on Thingiverse couldn't use a scad file I uploaded as he got an odd error. After a bit of too and fro (he speaks French, me not so much) it seems that skin.scad uses to_3d, vec3, and range from scad-utils but they are no longer in scad_utils. I guess I could flag on github (um, yes, my login details are ...) but both authors are active here, I think. Ian