404 Error on pagination with WP Query

Question

I have a website that is built almost entirely on the page.php template using Advanced custom fields flexible content field to determine what gets displayed. As part of that flexible content I have a reference field that fetches custom post types and displays a list of them.

This reference field's template looks like this and it sits inside the main WordPress loop.

    <?php 

  $margin = get_sub_field('remove_top_and_bottom_margin');

  if ($margin) {

    foreach($margin as $result) {

      if ($result == 'bottom') {
        $no_bottom = 'no-bottom-margin';
      }

      if ($result == 'top') {
        $no_top = 'no-top-margin';
      } 
    }

  }

?>

<?php 

// Here we choose the post type to reference. This post type 
// also has a flexible layout (see the get_template_part('templates/content', 'flexible'). 

$reference = get_sub_field('reference'); 

$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;

$args = array(

    "post_type" => $reference,
    "posts_per_page" => 1,
    "paged" => $paged

);

echo '<pre>';
var_dump($paged);
echo '</pre>';

$inner_query = new WP_Query($args); 

if ( $inner_query->have_posts() ) : ?>

  <div class="reference <?php echo $no_top . ' ' . $no_bottom; ?>">

    <?php   while ( $inner_query->have_posts() ) : $inner_query->the_post(); ?>

      <div class="reference-entity">

            <div class="entry-title">
          <h3><?php the_title(); ?></h3>
            <?php get_template_part('templates/entry-meta'); ?>
        </div>

            <?php get_template_part('templates/content', 'flexible');

            ?>

      </div>

    <?php endwhile; 

    if ($inner_query->max_num_pages > 1) :  // check if the max number of pages is greater than 1  ?>

      <nav class="prev-next-posts">
        <div class="prev-posts-link">
          <?php echo get_next_posts_link( 'Older Entries', $inner_query->max_num_pages ); // display older posts link ?>
        </div>
        <div class="next-posts-link">
          <?php echo get_previous_posts_link( 'Newer Entries' ); // display newer posts link ?>
        </div>
      </nav>

    <?php endif; 

    wp_reset_postdata(); ?>

  </div>

<?php else: 

  echo 'No posts found. Try adding one.';

endif; 

When I click the pagination link to go back I get a 404 Error and the URL has a /page/2 in it. Any help?

Answer 1

I have figured out the problem. There was a naming clash between my post type insights and the page name (also insights) which was confusing WordPress. Changing the post type to the singular insight fixed it.