Ali - I don't know what happened here, I was most certainly using version 10.xx - not sure which, but when I evaluate this now it doesn't work. The problem is the one mentioned by the OP here: http://community.wolfram.com/groups/-/m/t/1023182
There is a bug with DiscretizeGraphics where it isn't working on multi-polygons. Make this change in the definition of carto in either of the code blocks above and it should work
carto = DiscretizeGraphics[
CountryData["France", {"Polygon", "Mercator"}] /.
Polygon[x : {{{_, _} ..} ..}] :> Polygon /@ x];