Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, non-static method allow_php_in_posts::shortcode_advanced() cannot be called statically in /customers/9/b/f/skoyter.net/httpd.www/gil/wp-includes/class-wp-hook.php:288 Stack trace: #0 /customers/9/b/f/skoyter.net/httpd.www/gil/wp-includes/plugin.php(206): WP_Hook->apply_filters('