I tested the altsys 0.70 in XOOPS 2.3.2 and everything worked properly.

When I click on language, in the footer appear:

------------------------------------------
The overriding system cannot work with this XOOPS core except some D3 modules. If you want to enable it with this core, try to hack like this:

include/common.php
if ( file_exists(XOOPS_ROOT_PATH."/modules/"...."/main.php") ) {
include_once XOOPS_ROOT_PATH."/modules/"...."/main.php";
} else {
if ( file_exists(XOOPS_ROOT_PATH..../english/main.php") ) {
include_once XOOPS_ROOT_PATH..../english/main.php";
}
}
require_once XOOPS_TRUST_PATH."/libs/altsys/class/D3LanguageManager.class.php" ;
$langman =& D3LanguageManager::getInstance() ;
$langman->read( "main.php" , $xoopsModule->getVar("dirname") ) ;
----------------------------------

what that means?