Fatal error: Uncaught Error: Class "WP_Widget" not found in C:\xampp\htdocs\wordpress\wp-content\pluginsBK\wp-useronline\scb\Widget.php:5 Stack trace: #0 {main} thrown in C:\xampp\htdocs\wordpress\wp-content\pluginsBK\wp-useronline\scb\Widget.php on line 5