--- web/core/modules/field_ui/src/Form/EntityDisplayFormBase.php	2024-12-06 13:58:01.352870596 +0100
+++ web/core/modules/field_ui/src/Form/EntityDisplayFormBase_modified.php	2024-12-06 13:58:20.281645443 +0100
@@ -604,8 +604,18 @@
 
     // Collect data for 'regular' fields.
     foreach ($form['#fields'] as $field_name) {
-      $values = $form_values['fields'][$field_name];
+      // Check for NULL and empty array
+      if(isset($form_values['fields'][$field_name]) || is_null($form_values['fields'][$field_name])){
+        return; 
+      } 
+      else {
+        $values = $form_values['fields'][$field_name];
+      }
 
+      // Check for NULL.
+      if(is_null($values['region'])){
+        return;
+      }
       if ($values['region'] == 'hidden') {
         $entity->removeComponent($field_name);
       }