Thanks for your reply, Ilia.
1. It is exist (forum) information display as ????? (manual add before via phpMyAdmin as utf8 encode)on adm/admforum.php
2. It is already set 'charset=utf-8' at admpanel.php
source of /adm/admpanel.php
<head>
<link rel="StyleSheet" href="adm.css" type="text/css">
<meta http-equiv="Content-Type" content="text/html; charset=<?php
if (file_exists($DATA_DIR.'thm/'.$usr->theme_name.'/i18n/'.$usr->lang.'/charset')) {
echo trim(file_get_contents($DATA_DIR.'thm/'.$usr->theme_name.'/i18n/'.$usr->lang.'/charset'));
} else if (file_exists($DATA_DIR.'thm/default/i18n/'.$usr->lang.'/charset')) {
echo trim(file_get_contents($DATA_DIR.'thm/default/i18n/'.$usr->lang.'/charset'));
} else {
echo 'us-ascii';
}
?>">
</head>
Output of /adm/admforum.php
<head>
<link rel="StyleSheet" href="adm.css" type="text/css">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>