diff --git "a/typo3/sysext/backend/Classes/Controller/FormInlineAjaxController.php" "b/typo3/sysext/backend/Classes/Controller/FormInlineAjaxController - Kopie.php"
index c31ae49..4a26015 100644
--- "a/typo3/sysext/backend/Classes/Controller/FormInlineAjaxController.php"
+++ "b/typo3/sysext/backend/Classes/Controller/FormInlineAjaxController - Kopie.php"	
@@ -839,6 +839,9 @@ class FormInlineAjaxController
             if (!isset($childConfig[$flexFormNode]) && preg_match('/^[lv][[:alpha:]]+$/', $flexFormNode)) {
                 continue;
             }
+            if (!isset($childConfig[$flexFormNode]) && preg_match('/^[[:digit:]]+$/', $flexFormNode)) {
+                continue;
+            }
             $childConfig = $childConfig[$flexFormNode];
 
             // Skip to the field configuration of a sheet