diff --git a/src/Form/ConditionalFieldForm.php b/src/Form/ConditionalFieldForm.php
index b6f9c6b..e64b0a0 100644
--- a/src/Form/ConditionalFieldForm.php
+++ b/src/Form/ConditionalFieldForm.php
@@ -138,6 +138,7 @@ class ConditionalFieldForm extends FormBase {
         // Validate required field should be visible.
         $field_instance = $instances[$field];
         if (
+          method_exists($field_instance, 'isRequired') &&
           $field_instance->isRequired() &&
           in_array($state, ['!visible', 'disabled', '!required'])
         ) {
@@ -248,6 +249,13 @@ class ConditionalFieldForm extends FormBase {
       $fields[$field->getName()] = $field->getLabel() . ' (' . $field->getName() . ')';
     }
 
+    if (\Drupal::moduleHandler()->moduleExists('field_group')) {
+      $group_info = field_group_info_groups($entity_type, $bundle_name, 'form', 'default');
+      foreach ($group_info as $name => $group) {
+        $fields[$name] = $group->label . ' (' . $name . ')';
+      }
+    }
+
     asort($fields);
 
     /* Existing conditions. */