Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, non-static method Products::setProductsPerPage() cannot be called statically in /usr/www/users/irishm/wp-includes/class-wp-hook.php:324 Stack trace: #0 /usr/www/users/irishm/wp-includes/plugin.php(205): WP_Hook->apply_filters() #1 /usr/www/users/irishm/wp-content/plugins/woocommerce/includes/class-wc-query.php(505): apply_filters() #2 /usr/www/users/irishm/wp-content/plugins/woocommerce/includes/class-wc-query.php(391): WC_Query->product_query() #3 /usr/www/users/irishm/wp-includes/class-wp-hook.php(324): WC_Query->pre_get_posts() #4 /usr/www/users/irishm/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters() #5 /usr/www/users/irishm/wp-includes/plugin.php(565): WP_Hook->do_action() #6 /usr/www/users/irishm/wp-includes/class-wp-query.php(1881): do_action_ref_array() #7 /usr/www/users/irishm/wp-includes/class-wp-query.php(3824): WP_Query->get_posts() #8 /usr/www/users/irishm/wp-includes/class-wp.php(696): WP_Query->query() #9 /usr/www/users/irishm/wp-includes/class-wp.php(816): WP->query_posts() #10 /usr/www/users/irishm/wp-includes/functions.php(1336): WP->main() #11 /usr/www/users/irishm/wp-blog-header.php(16): wp() #12 /usr/www/users/irishm/index.php(17): require('/usr/www/users/...') #13 {main} thrown in /usr/www/users/irishm/wp-includes/class-wp-hook.php on line 324