Fix bug with NextGen Gallery and Checkout for WooCommerce

nextgen-gallery.php

<?php

// Include in functions.php file or with your favorite snippets plugin
// Do NOT include opening PHP tag above (<?php)

add_filter(
	'run_ngg_resource_manager', function( $valid_request ) {
		if ( ! empty( $_GET['wc-ajax'] ) ) {
			return false;
		}

		return $valid_request;
	}
);