Q:

Can't get ACF repeater data in category template

I have a custom post type for architectural projects which includes, among other things, an ACF repeater which contains an image, its title, and its description. This repeater is turned into a slideshow on the individual project (post) page. 
Each project is also assigned to one or more categories (housing, medical, etc.)
On the category page for these projects, I want to pull down the first image for each project to use as a thumbnail.
My code in the category template looks something like this:
<?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>
<pre><?php print_r( get_field('images') ) ?> </pre><!-- for debugging -->

    <div class="col-xs-4 col-md-2">
        <figure class="show-caption">

        <?php if( have_rows('images') ): the_row(); ?>
            <?php $photo = get_sub_field('photo'); $filename = $photo['sizes']['large']; ?>
            <a href="<?php the_permalink() ?>" class="thumbnail"><img src="<?= $filename ?>" width="250" height="166" alt=""></a>
        <?php endwhile; endif; ?>

        </figure>
    </div>

<?php endif; ?>

The problem is, have_rows('images') returns false on the category template page, but true on the project page. And when I print_r( get_field('images') ) on both pages, I get the full array of images on the project page, but only an integer (equal to the array size) on the category page.
How can I see the full array of images on the category page?

A:

Finally found this solution on the ACF support forums. All I had to do was add this to my functions.php file in my custom theme:
//Include CPT In Categories Pages
function namespace_add_custom_types( $query ) {
    if( is_category() || is_tag() && empty( $query->query_vars['suppress_filters'] ) ) {
        $post_types = get_post_types( '', 'names' ); 
        $query->set( 'post_type', $post_types);
        return $query;
    }
}
add_filter( 'pre_get_posts', 'namespace_add_custom_types');

