fix

lib/web/mage/menu.js

@@ -641,7 +641,9 @@ define([
             });
             });
             var self = this
             var self = this
             $('div.submenu.shown').each(function () {
             $('div.submenu.shown').each(function () {
-                if (dropdown.parent('li')[0].className != $(this).parent('li')[0].className) {
+                if (dropdown.length > 0 && dropdown.parent('li')[0].className != $(this).parent('li')[0].className) {
+                    self.close($(this));
+                } else if(dropdown.length == 0){
                     self.close($(this));
                     self.close($(this));
                 }
                 }