Once you have tried the above steps, email david@coppit.org with the results of these debugging steps. Also include the following information:

Original HTML:
<li class="cat-item cat-item-4"><a href="https://www.vwv11.com/category/blog" >Blog</a> (42)
<ul class='children'>
<li class="cat-item cat-item-20"><a href="https://www.vwv11.com/category/blog/food" >Food</a> (3)
</li>
<li class="cat-item cat-item-9"><a href="https://www.vwv11.com/category/blog/news" >News</a> (24)
</li>
<li class="cat-item cat-item-8"><a href="https://www.vwv11.com/category/blog/publication" >Publication</a> (13)
</li>
<li class="cat-item cat-item-16"><a href="https://www.vwv11.com/category/blog/review" >Review</a> (2)
</li>
</ul>
</li>
<li class="cat-item cat-item-13"><a href="https://www.vwv11.com/category/download" >Download</a> (5)
</li>
<li class="cat-item cat-item-5"><a href="https://www.vwv11.com/category/exhibition" >Exhibition</a> (18)
</li>
<li class="cat-item cat-item-3"><a href="https://www.vwv11.com/category/works" >Works</a> (2)
</li>

Processed HTML:
<li class="cat-item cat-item-4"><a href="https://www.vwv11.com/category/blog" >Blog</a> (42)

<li class="cat-item cat-item-20"><a href="https://www.vwv11.com/category/blog/food" >Food</a> (3)
</li>
<li class="cat-item cat-item-9"><a href="https://www.vwv11.com/category/blog/news" >News</a> (24)
</li>
<li class="cat-item cat-item-8"><a href="https://www.vwv11.com/category/blog/publication" >Publication</a> (13)
</li>
<li class="cat-item cat-item-16"><a href="https://www.vwv11.com/category/blog/review" >Review</a> (2)
</li>

<li class="cat-item cat-item-13"><a href="https://www.vwv11.com/category/download" >Download</a> (5)
</li>
<li class="cat-item cat-item-5"><a href="https://www.vwv11.com/category/exhibition" >Exhibition</a> (18)
</li>
<li class="cat-item cat-item-3"><a href="https://www.vwv11.com/category/works" >Works</a> (2)
</li>

Category pattern:
/http\:\/\/www\.vwv11\.com.*?\/category\/(?:[^\/"]+\/)*([^\/"]+)/

Items:
Array
(
    [0] => <li class="cat-item cat-item-4"><a href="https://www.vwv11.com/category/blog" >Blog</a> (42)</li>
    [1] => <li class="cat-item cat-item-20"><a href="https://www.vwv11.com/category/blog/food" >Food</a> (3) </li>
    [2] => <li class="cat-item cat-item-9"><a href="https://www.vwv11.com/category/blog/news" >News</a> (24) </li>
    [3] => <li class="cat-item cat-item-8"><a href="https://www.vwv11.com/category/blog/publication" >Publication</a> (13) </li>
    [4] => <li class="cat-item cat-item-16"><a href="https://www.vwv11.com/category/blog/review" >Review</a> (2) </li>
    [5] => <li class="cat-item cat-item-13"><a href="https://www.vwv11.com/category/download" >Download</a> (5) </li>
    [6] => <li class="cat-item cat-item-5"><a href="https://www.vwv11.com/category/exhibition" >Exhibition</a> (18) </li>
    [7] => <li class="cat-item cat-item-3"><a href="https://www.vwv11.com/category/works" >Works</a> (2) </li>
)