Fatal error: Uncaught Error: Call to undefined function Nextend\Framework\Platform\WordPress\is_admin() in C:\xampp\htdocs\wp-content\plugins\smart-slider-3\Nextend\Framework\Platform\WordPress\PlatformWordPress.php:19 Stack trace: #0 C:\xampp\htdocs\wp-content\plugins\smart-slider-3\Nextend\Framework\Platform\Platform.php(19): Nextend\Framework\Platform\WordPress\PlatformWordPress->__construct() #1 C:\xampp\htdocs\wp-content\plugins\smart-slider-3\Nextend\Framework\Pattern\SingletonTrait.php(12): Nextend\Framework\Platform\Platform->__construct() #2 C:\xampp\htdocs\wp-content\plugins\smart-slider-3\Nextend\Framework\Platform\Platform.php(89): Nextend\Framework\Platform\Platform::getInstance() #3 C:\xampp\htdocs\wp-content\plugins\smart-slider-3\Nextend\Autoloader.php(194): require('C:\\xampp\\htdocs...') #4 C:\xampp\htdocs\wp-content\plugins\smart-slider-3\Nextend\Autoloader.php(175): Nextend\Autoloader->requireFile('C:\\xampp\\htdocs...') #5 C:\xampp\htdocs\wp-content\plugins\smart-slider-3\Nextend\Autoloader.php(128): in C:\xampp\htdocs\wp-content\plugins\smart-slider-3\Nextend\Framework\Platform\WordPress\PlatformWordPress.php on line 19