Action: Create item

I has created a rule with 2 actions after a node creation:

• The first create a menu item linked to the created node, and have Main menu as parent (works), and provide a variable
• The second should create a menu item linked to the created node, and should have as parent the firstly created menu item.

At the second step, I got the error then creating a node:

Notice: Undefined offset: 1 in menu_rules_create_item() (line 312 of [...]/sites/all/modules/menu_rules/menu_rules.rules.inc).

I looked for theses lines:

  if (is_numeric($menu_parent)) {
    $item['plid'] = $menu_parent;
  }
  elseif (strpos($menu_parent, ':')) {
    list($item['menu_name'], $item['plid']) = explode(':', $menu_parent);
  }
  list($item['menu_name'], $item['plid']) = explode(':', $menu_parent); // line 312

This line is the same as the one in elseif condition.