Unhandled Error!

Trying to get property of non-object

Document Post
Document type CMS page
Line 13
Exception class Cms_ExecutionException

Code Highlight

                  itemtype="https://schema.org/ListItem"><a href="<?php echo site_url('/blog/'); ?>" itemprop="item"><span itemprop="name">Blog</span><meta itemprop="position" content="2" /></a></span> &nbsp;>&nbsp;
            <?php if (isset($post->categories[0])): ?>
            <span itemprop="itemListElement" itemscope
                  itemtype="https://schema.org/ListItem"><a href="/blog/category/<?php echo $post->categories[0]->url_name; ?>/" itemprop="item"><span itemprop="name"><?php echo $post->categories[0]->name; ?></span></a> &nbsp;>&nbsp;<meta itemprop="position" content="3" /></span>
            <?php endif; ?>
            <span itemprop="itemListElement" itemscope
                  itemtype="https://schema.org/ListItem"><span itemprop="name"><?php echo $post->title; ?></span><meta itemprop="position" content="<?php if (isset($post->categories[0])): ?>4<?php else: ?>3<?php endif; ?>" /></span>
        </div>
    </div>
</div>
 
<section class="content">
 
# Document Type
1 Post CMS page