prevents regression on EmailFinisher::getRecipients method

ot_templating/Classes/XClass/Form/Finishers/EmailFinisher.php

@@ -15,7 +15,10 @@ class EmailFinisher extends \TYPO3\CMS\Form\Domain\Finishers\EmailFinisher
     protected function getRecipients(string $listOption): array {
         if ($listOption === 'recipients') {
             $address = $this->parseOption($listOption) ?? null;
-            return $address ? [new Address($address, 'Contact')] : [];
+
+            if ($address && is_string($address)) {
+                return [new Address($address, 'Contact')];
+            }
         }
         return parent::getRecipients($listOption);
     }