Thank you for the answer @wreckingadm
In fact, I replacing the line:
('#top-menu, #main-menu').find('li').on('hover', function () {
by this :
$('#top-menu, #main-menu').find('li').hover(function () {
The drop-down menus work again.
I’m Not being a programmer, I could have looked for a long time.
Thank you very much for helping out ??