it's strange, this is the main.php:
// $Id: mainfile.php,v 1.6 2003/02/12 03:37:37 okazu Exp $
// ------------------------------------------------------------------------ //
// XOOPS - PHP Content Management System //
// Copyright (c) 2000 XOOPS.org //
// <
https://xoops.org/> //
// ------------------------------------------------------------------------ //
// This program is free software; you can redistribute it and/or modify //
// it under the terms of the GNU General Public License as published by //
// the Free Software Foundation; either version 2 of the License, or //
// (at your option) any later version. //
// //
// You may not change or alter any portion of this comment or credits //
// of supporting developers from this source code or any supporting //
// source code which is considered copyrighted (c) material of the //
// original comment or credit authors. //
// //
// This program is distributed in the hope that it will be useful, //
// but WITHOUT ANY WARRANTY; without even the implied warranty of //
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //
// GNU General Public License for more details. //
// //
// You should have received a copy of the GNU General Public License //
// along with this program; if not, write to the Free Software //
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA //
// ------------------------------------------------------------------------ //
/**
* XOOPS is not installed, redirect to the installer
**/
// XOOPS is not installed yet.
if(! defined('XOOPS_INSTALL')){
header('Location: install/index.php');
}
?>