Fatal error: Uncaught Error: Interface "Inpsyde\Zettle\PhpSdk\Validator\ValidatorInterface" not found in /var/www/html1/wp-content/plugins/zettle-pos-integration/modules/zettle-php-sdk/src/Validator/VariantOptionDefinitionsValidator.php:17 Stack trace: #0 {main} thrown in /var/www/html1/wp-content/plugins/zettle-pos-integration/modules/zettle-php-sdk/src/Validator/VariantOptionDefinitionsValidator.php on line 17