Первым делом вы должны удалить встроенное событие javascript и попробовать следующее, например:
jQuery:
$('.dropdown').click(function(event){
event.stopPropagation();
$('.dropdown-menu').toggle();
})
$('.project__body').click(function(){
window.location.href="next.html"
})
html:
<div class="project__body">
<div class="row">
<div class="col-10">
<h1>Title of the DIV!</h1>
</div>
<div class="col-2 text-right">
<div class="dropdown">
<button type="button" class="dropdown-btn dropdown-toggle" data-toggle="dropdown">Menu</button>
<div class="dropdown-menu dropdown-menu-right">
<a class="dropdown-item" href="#">Edit</a>
<a class="dropdown-item" href="#">Delete</a>
</div>
</div>
</div>
</div>
<div class="row">
<div class="col-12">
<p>There's more content here in this div. There's more content here in this div. There's more content here in this div. </p>
</div>
</div>