Hello Folks,
 
What means the next line?

 [11-Dec-2012 16:10:08] PHP Warning:  strtolower() expects parameter 1 to be string, array given in ../roundcubemail-0.8.4/program/include/rcmail.php on line 423


  public function get_address_book($id, $writeable = false)
  {
    $contacts    = null;
    $ldap_config = (array)$this->config->get('ldap_public');
// The next line is the numer 423
    $abook_type  = strtolower($this->config->get('address_book_type'));

    // 'sql' is the alias for '0' used by autocomplete
    if ($id == 'sql')
        $id = '0';

    // use existing instance
    if (isset($this->address_books[$id]) && is_object($this->address_books[$id])
      && is_a($this->address_books[$id], 'rcube_addressbook')
      && (!$writeable || !$this->address_books[$id]->readonly)
    ) {
      $contacts = $this->address_books[$id];
    }
    else if ($id && $ldap_config[$id]) {
      $contacts = new rcube_ldap($ldap_config[$id], $this->config->get('ldap_debug'), $this->config->mail_domain($_SESSION['storage_host']));
    }
    else if ($id === '0') {
      $contacts = new rcube_contacts($this->db, $this->user->ID);
    }
    else {
      $plugin = $this->plugins->exec_hook('addressbook_get', array('id' => $id, 'writeable' => $writeable));

      // plugin returned instance of a rcube_addressbook
      if ($plugin['instance'] instanceof rcube_addressbook) {
        $contacts = $plugin['instance'];
      }
      // get first source from the list
      else if (!$id) {
        $source = reset($this->get_address_sources($writeable));
        if (!empty($source)) {
          $contacts = $this->get_address_book($source['id']);
          if ($contacts)
            $id = $source['id'];
        }
      }
    }

    if (!$contacts) {
      raise_error(array(
        'code' => 700, 'type' => 'php',
        'file' => __FILE__, 'line' => __LINE__,
        'message' => "Addressbook source ($id) not found!"),
        true, true);
    }

    // set configured sort order
    if ($sort_col = $this->config->get('addressbook_sort_col'))
        $contacts->set_sort_order($sort_col);

    // add to the 'books' array for shutdown function
    $this->address_books[$id] = $contacts;

    return $contacts;
  }

Regards,

Reymer Vargas