Fix the_content() Not Working in a Custom Post Type Template

In a single-{post_type}.php template, such as single-book.php for a post type called book, the_content() can print nothing when you call it on its own. It relies on the post data that the_post() sets up, so it has to run inside the Loop.

The fix: wrap your template code in the Loop

Put the part of the template that displays the post inside this structure:

<?php if(have_posts()): while(have_posts()): the_post(); ?>
//your code for the content
<?php echo wpautop( the_content() ); ?> 
<?php endwhile; endif;?>

• have_posts() checks that WordPress found a post for the current URL, and the_post() makes it the current post, so template tags such as the_content(), the_title() and the_post_thumbnail() know what to show.
• Replace the //your code for the content line with your own markup. It sits outside the PHP tags, so if you leave it in, it prints on the page as plain text.
• the_content() prints the content itself and returns nothing, so the wpautop() wrapper around it has no effect. Your paragraphs still appear, because the_content() runs the content filters, which normally include wpautop(). A plain <?php the_content(); ?> gives the same result.

If the single page shows a 404 error instead of an empty content area, the cause is different: re-save Settings > Permalinks to refresh the rewrite rules, as covered in fixing 404 errors on custom post type pages.

Related articles

• getting post content from an ACF Relationship field: why the_content() can’t take a post ID
• splitting a post into pages with wp_link_pages(): another template tag that needs the Loop