This guide will show you how to disable the parent navigation link to prevent empty pages. It is applicable to all multipurpose templates with a standard dropdown menu.
All you have to do is to place the following code in Settings> Edit Head
<style type="text/css">
/*<![CDATA[*/
/* Disable first level nav links with children and current level of breadcrumb menu */
.cc-pagemode-default .hs-menu li.jmd-nav__list-item-0.j-nav-has-children > a,
.cc-pagemode-default li.jmd-nav__list-item-0.j-nav-has-children > a:not(li.jmd-nav__list-item-1.j-nav-has-children a),
.j-nav-variant-breadcrumb li a:not(.j-nav-current) {
cursor: default !important;
pointer-events: none!important;
}
/*]]>*/
</style>