diff --git a/typo3/sysext/form/Classes/Domain/Configuration/FlexformConfiguration/Processors/FinisherOptionGenerator.php b/typo3/sysext/form/Classes/Domain/Configuration/FlexformConfiguration/Processors/FinisherOptionGenerator.php
index ec9ef4fc3ac0a14098b5955bb94690f22c4976f6..1ac281f2edd0b236e0b38bee44aa29f8606ded48 100644
--- a/typo3/sysext/form/Classes/Domain/Configuration/FlexformConfiguration/Processors/FinisherOptionGenerator.php
+++ b/typo3/sysext/form/Classes/Domain/Configuration/FlexformConfiguration/Processors/FinisherOptionGenerator.php
@@ -72,17 +72,21 @@ class FinisherOptionGenerator extends AbstractProcessor
         } catch (MissingArrayPathException $exception) {
         }
 
+        if (isset($elementConfiguration['config'])) {
+            $elementConfiguration['config']['default'] = $optionValue;
+        }
+
         $languageService = $this->getLanguageService();
+        $elementConfiguration['label'] = (string)($elementConfiguration['label'] ?? '');
         if (empty($optionValue)) {
             $elementConfiguration['label'] .= sprintf(' (%s: "%s")', $languageService->getLL('default'), $languageService->getLL('empty'));
         } else {
+            if (is_array($optionValue)) {
+                $optionValue = implode(',', $optionValue);
+            }
             $elementConfiguration['label'] .= sprintf(' (%s: "' . $optionValue . '")', $languageService->getLL('default'));
         }
 
-        if (isset($elementConfiguration['config'])) {
-            $elementConfiguration['config']['default'] = $optionValue;
-        }
-
         $sheetElements = $this->converterDto->getResult();
         $sheetElements['settings.finishers.' . $finisherIdentifier . '.' . $optionKey]['TCEforms'] = $elementConfiguration;