Fatal error: Uncaught Error: Using $this when not in object context in C:\xampp\htdocs\wp-content\plugins\admin-columns-pro\templates\admin\onboarding-menu.php:8 Stack trace: #0 {main} thrown in C:\xampp\htdocs\wp-content\plugins\admin-columns-pro\templates\admin\onboarding-menu.php on line 8