Issue #3427263: Attempt to assign property "options" on null

menu_manipulator.module

@@ -191,6 +191,11 @@ function menu_manipulator_form_menu_link_content_form_alter(array &$form, FormSt
  * Entity builder for menu item entity form.
  */
 function menu_manipulator_menu_link_content_form_entity_builder($entity_type, EntityInterface $menu_link, &$form, FormStateInterface $form_state) {
+  // Don't do anything when we have no link.
+  if (!$menu_link->link || $menu_link->link->isEmpty()) {
+    return;
+  }
+
   // Attach extra options to Menu Link Content entity.
   $menu_link_options = $menu_link->link->first()->options ?: [];
   $menu_link_options['icon'] = $form_state->getValue('menu_link_icon');