As irmtfan wrote, it might be caused by editing langauge files wrongly.
How to find "the wrong point":
- turn "PHP debug" on.
- set "Module for your start page" none
- edit index.php like this
/**
* redirects to installation, if xoops is not installed yet
**/
include "mainfile.php";
//check if start page is defined
if ( isset($xoopsConfig['startpage']) && $xoopsConfig['startpage'] != "" && $xoopsConfig['startpage'] != "--" ) {
header('Location: '.XOOPS_URL.'/modules/'.$xoopsConfig['startpage'].'/');
exit();
} else {
$xoopsOption['show_cblock'] =1;
include "header.php";
header('');
include "footer.php";
}
?>
You get warning.
It tells us which file is wrong.