Ok found how to resolve it :
In admin/index.php :
Remplace line 63 to 85 by :
//load the main skin
$settings_file = SITE_ROOT . 'admin/lib/'.$tplname.'/'.$tplname.'.php';
if(file_exists($settings_file)) {
include $settings_file;
}
Template::setTemplatePath(SITE_ROOT.'admin/templates');
Template::setSkinPath(SITE_ROOT.'admin/lib/'.$tplname);
$BaseTemplate->template_path = SITE_ROOT.'admin/lib/'.$tplname;
$BaseTemplate->skin_path = SITE_ROOT.'admin/lib/'.$tplname;
$BaseTemplate->Set('title', SITE_NAME);
Template::Set('MODULE_NAV_INC', $NAVBAR);
Template::Set('MODULE_HEAD_INC', $HTMLHead);
$BaseTemplate->show('header.php');
flush();
MainController::runAllActions();
$BaseTemplate->show('footer.php');
rename header.tpl to header.php and the same for footer...
Edit : check inside header.php and footer.php there are remaining tpl sources...
Edit 2 : all modules are calling for tpl files... need to change it too