И заодно выложите здесь Ваш файл jsloader.php,

<?php
/****************************************************************************
* ExBB v.1.9 *
* Copyright (c) 2002-20хх by Alexander Subhankulov aka Warlock *
* *
* http://www.exbb.revansh.com *
* email: admin@exbb.revansh.com *
* *
****************************************************************************/
/****************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
****************************************************************************/
define('NO_GZIP', TRUE);
define('IN_EXBB', TRUE);
include('./include/common.php';

// Load JsHttpRequest backend.
require_once "include/JsHttpRequest/JsHttpRequest.php";
// Create main library object. You MUST specify page encoding!
$JsHttpRequest =& new JsHttpRequest($fm->LANG['ENCODING']);

$fm->_GetVars();
$fm->_String('loader';
$fm->_String('action';

$_RESULT = array(
"error" => 1
);

if ($fm->input['loader'] === 'karma'{
include('modules/karma/karma.php';
} elseif ($fm->input['loader'] === 'threadstop'{

} else if ($fm->input['loader'] == 'verify' {
include('include/JsHttpRequest/verify_forms.php';


include('modules/threadstop/threadstop.php';
} elseif ($fm->input['loader'] === 'relatedtop'{
include('modules/relatedtop/backend.php';
} elseif ($fm->input['loader'] === 'chat'{
require_once('modules/chat/backend.php';
} elseif ($fm->input['loader'] === 'newmail'{
if ($fm->exbb['pm'] === FALSE && !defined('IS_ADMIN') {
echo $fm->LANG['PMClosed'];
}

if ($fm->user['id'] === 0) {
echo $fm->LANG['UserUnreg'];
}

if ($fm->user['new_pm'] === TRUE) {
$user = $fm->_Read2Write($fp_user,'members/'.$fm->user['id'].'.php',FALSE);
$user['new_pm'] = $fm->user['new_pm'] = FALSE;
$fm->_Write($fp_user,$user);
unset($user);
}
$_RESULT["error"] = 0;
die();
} elseif ($fm->input['loader'] === 'preview'{
if ($fm->input['action'] === 'news' && defined('IS_ADMIN') {
$_RESULT["error"] = 0;
echo $fm->formatpost($fm->input['text'],$fm->_Boolean($fm->input,'html');
} elseif ($fm->input['action'] === 'newtopic' {
$_RESULT["error"] = 0;
echo $fm->formatpost($fm->input['text'],$fm->_Boolean($fm->input,'html');
} else {
echo $fm->LANG['CorrectPost'];
}
die();
} else {
echo $fm->LANG['ModNotInstalled'];
}
?>