It looks like Two Column and Two Column Collapse One in Components > Layouts each seem to have extra closing div tags in the example text. E.g. the example for Two Column Collapse One reads:
<article class="cf">
<div class="fl w-100 w-50-ns bg-near-white tc">
<h1>Column One</h1>
</div>
<div class="fl w-100 w-50-ns bg-light-gray tc">
<h1>Column Two</h1>
</div>
**</div>**
</article>