Instructions to get the plugin working again

WooCommerce changed the way it stores catalog visibility since the last time the plugin was updated. With a quick edit to one file, you can (as of October 2022) get it working again.

Edit this file:

wp-content/plugins/woocommerce-sold-out-products/classes/class-wc-sold-out-products.php

Remove or comment out this block of code that starts on line 64:

		$meta_query[] = array(
			'key'     => '_visibility',
			'value'   => array( 'visible', 'catalog' ),
			'compare' => 'IN'
		);

Replace the $args definition starting on line 95 with the code below (the tax_query portion is the new piece):

		$args = array(
			'post_type'	=> 'product',
			'post_status' => 'publish',
			'ignore_sticky_posts'	=> 1,
			'posts_per_page' => $per_page,
			'orderby' => $orderby,
			'order' => $order,
			'meta_query' => $meta_query,
			'tax_query'   => array( array(
				'taxonomy'  => 'product_visibility',
				'terms'     => array( 'exclude-from-catalog' ),
				'field'     => 'name',
				'operator'  => 'NOT IN',
			) )
		);