Lupin III is banned in France because it is violating French copyright laws(he's the grandson of a French literary character of the same name). Inspector Gadget was originally going to be a spin-off of Lupin set in the future, with the titular Inspector Gadget being the grandson of Inspector Zenigata, but some arcane French copyright laws applied to Quebec somehow, which was where the show was being made, so they had to completely file off anything identifiable as Lupin.