Fatal error: Uncaught Error: Interface "PayPalHttp\Serializer" not found in C:\xampp\htdocs\wp-content\plugins\nextgen-gallery-pro\modules\paypal_checkout\vendor\paypal\paypalhttp\lib\PayPalHttp\Serializer\Text.php:14 Stack trace: #0 {main} thrown in C:\xampp\htdocs\wp-content\plugins\nextgen-gallery-pro\modules\paypal_checkout\vendor\paypal\paypalhttp\lib\PayPalHttp\Serializer\Text.php on line 14