Fatal error: Uncaught Error: Class 'Nextend\Framework\Form\Base\PlatformFormBase' not found in C:\xampp\htdocs\wp-content\plugins\smart-slider-3\Nextend\Framework\Form\WordPress\PlatformForm.php:8 Stack trace: #0 {main} thrown in C:\xampp\htdocs\wp-content\plugins\smart-slider-3\Nextend\Framework\Form\WordPress\PlatformForm.php on line 8