Fatal error: Uncaught Error: Class "PayPal\Common\PayPalModel" not found in C:\xampp\htdocs\wp-content\plugins\nextgen-gallery-pro\modules\paypal_checkout\vendor\paypal\rest-api-sdk-php\lib\PayPal\Api\Measurement.php:17 Stack trace: #0 {main} thrown in C:\xampp\htdocs\wp-content\plugins\nextgen-gallery-pro\modules\paypal_checkout\vendor\paypal\rest-api-sdk-php\lib\PayPal\Api\Measurement.php on line 17