글쓰기 html 오류

글쓰기 html 체크하고 글을 올리면 이런 오류메세지가 뜹니다.

도와주세요~!!

Warning: include_once(/public_html/plugin/htmlpurifier/HTMLPurifier.standalone.php): failed to open stream: No such file or directory in public_html/lib/common.lib.php on line 561

Warning: include_once(): Failed opening '/public_html/plugin/htmlpurifier/HTMLPurifier.standalone.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in public_html/lib/common.lib.php on line 561

Fatal error: Class 'HTMLPurifier_Config' not found in /public_html/lib/common.lib.php on line 562 

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    // 내 도메인도 추가
    array_push($domains, $_SERVER['HTTP_HOST'].'/');
    $safeiframe = implode('|', $domains);

    include_once(G5_PLUGIN_PATH.'/htmlpurifier/HTMLPurifier.standalone.php');
    $config = HTMLPurifier_Config::createDefault();
    // data/cache 디렉토리에 CSS, HTML, URI 디렉토리 등을 만든다.
    $config->set('Cache.SerializerPath', G5_DATA_PATH.'/cache');
    $config->set('HTML.SafeEmbed', false);
    $config->set('HTML.SafeObject', false);
    $config->set('Output.FlashCompat', false);
    $config->set('HTML.SafeIframe', true);
    $config->set('URI.SafeIframeRegexp','%^(https?:)?//('.$safeiframe.')%');
    $config->set('Attr.AllowedFrameTargets', array('_blank'));
    $purifier = new HTMLPurifier($config);
    return $purifier->purify($html);
}