Fatal error: PHP notice in file /home/www/nimri/board/wcf/lib/system/session/CookieSessionFactory.class.php (121): Use of undefined constant COOKIE_PREFIX - assumed 'COOKIE_PREFIX'

Information:

error message: PHP notice in file /home/www/nimri/board/wcf/lib/system/session/CookieSessionFactory.class.php (121): Use of undefined constant COOKIE_PREFIX - assumed 'COOKIE_PREFIX'
error code: 0
file: /home/www/nimri/board/wcf/lib/system/WCF.class.php (255)
php version: 5.3.5
wcf version: 1.0.11 pl 3 (Horizon)
date: Sat, 28 Jan 2012 09:01:57 +0000
request: /
referer:

Stacktrace:

#0 /home/www/nimri/board/wcf/lib/system/session/CookieSessionFactory.class.php(121): WCF::handleError(8, 'Use of undefine...', '/home/www/nimri...', 121, Array)
#1 /home/www/nimri/board/wcf/lib/system/session/SessionFactory.class.php(61): CookieSessionFactory->readSessionID()
#2 /home/www/nimri/board/lib/system/WBBCore.class.php(201): SessionFactory->get()
#3 /home/www/nimri/board/wcf/lib/system/WCF.class.php(91): WBBCore->initSession()
#4 /home/www/nimri/board/global.php(18): WCF->__construct()
#5 /home/www/nimri/board/index.php(9): require_once('/home/www/nimri...')
#6 {main}