Fatal error: Uncaught Error: Class 'WP_Upgrader_Skin' not found in /home/refref/public_html/csv-importer/wordfence/class-plugin-installer-skin.php:18 Stack trace: #0 {main} thrown in /home/refref/public_html/csv-importer/wordfence/class-plugin-installer-skin.php on line 18