Question

Cannot modify header information – headers already sent by (output started at /wp-includes/class-wp-post-type.php:613) in /wp-includes/functions.php on line 6029

This error has seemed to follow me around since WP 5.3 where ‘supports’ needs to be an array. I’ve been able to successfully clear out the error for a small handful of sites by changing the order of the CPT args (throwing ‘supports’ at the end), but on others, the error still persists. I’ve always used an array for ‘supports’, but for some reason, this error is still persisting… Maybe it’s something else in the CPT? I know it’s the CPT for sure because removing the CPT code resolves the error. Can anyone tell me what I’m missing?

function rich_review() {

$labels = array( 'name' => _x( 'Reviews', 'Post Type General Name', 'text_domain' ), 'singular_name' => _x( 'Review', 'Post Type Singular Name', 'text_domain' ), 'menu_name' => __( 'Reviews', 'text_domain' ), 'name_admin_bar' => __( 'Reviews', 'text_domain' ), 'archives' => __( 'Review Archives', 'text_domain' ), 'attributes' => __( 'Review Attributes', 'text_domain' ), 'parent_item_colon' => __( 'Parent Item:', 'text_domain' ), 'all_items' => __( 'All Items', 'text_domain' ), 'add_new_item' => __( 'Add New Item', 'text_domain' ), 'add_new' => __( 'Add New', 'text_domain' ), 'new_item' => __( 'New Item', 'text_domain' ), 'edit_item' => __( 'Edit Item', 'text_domain' ), 'update_item' => __( 'Update Item', 'text_domain' ), 'view_item' => __( 'View Item', 'text_domain' ), 'view_items' => __( 'View Items', 'text_domain' ), 'search_items' => __( 'Search Item', 'text_domain' ), 'not_found' => __( 'Not found', 'text_domain' ), 'not_found_in_trash' => __( 'Not found in Trash', 'text_domain' ), 'featured_image' => __( 'Featured Image', 'text_domain' ), 'set_featured_image' => __( 'Set featured image', 'text_domain' ), 'remove_featured_image' => __( 'Remove featured image', 'text_domain' ), 'use_featured_image' => __( 'Use as featured image', 'text_domain' ), 'insert_into_item' => __( 'Insert into item', 'text_domain' ), 'uploaded_to_this_item' => __( 'Uploaded to this item', 'text_domain' ), 'items_list' => __( 'Items list', 'text_domain' ), 'items_list_navigation' => __( 'Items list navigation', 'text_domain' ), 'filter_items_list' => __( 'Filter items list', 'text_domain' ), );$args = array(
'label'                 => __( 'Review', 'text_domain' ),
'description'           => __( 'Rich reviews', 'text_domain' ),
'labels'                => $labels, 'taxonomies' => 'rich_review_tax', 'hierarchical' => false, 'public' => true, 'show_ui' => true, 'show_in_menu' => true, 'menu_position' => 5, 'show_in_admin_bar' => true, 'show_in_nav_menus' => true, 'can_export' => true, 'has_archive' => true, 'exclude_from_search' => false, 'publicly_queryable' => true, 'capability_type' => 'page', 'supports' => array('title', 'editor'), ); register_post_type( 'reviews',$args );

}