See: http://xoops.org/modules/newbb/viewtopic.php?post_id=344657#forumpost344657
Fix by XavierS:
line 86
if (!@copy($vars['VAR_PATH'] . '/data/secure.dist.php', $vars['VAR_PATH'] . '/data/secure.php')) {
$error = ERR_COPY_MAINFILE.$vars['VAR_PATH'] . '/data/secure.dist.php';
} else {
clearstatcache();
$rewrite = array_merge($rewrite, $vars);
Fixed in SVN and waiting for review