Fatal error: Uncaught Error: Using $this when not in object context in C:\xampp\htdocs\wp-content\plugins\smart-slider-3\Nextend\SmartSlider3\Application\Admin\Layout\Block\Slide\SlideManager\SlideManager.php:18 Stack trace: #0 {main} thrown in C:\xampp\htdocs\wp-content\plugins\smart-slider-3\Nextend\SmartSlider3\Application\Admin\Layout\Block\Slide\SlideManager\SlideManager.php on line 18