Fatal error: PHP notice in file /home/propalit/public_html/forum/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/propalit/public_html/forum/wcf/lib/system/session/CookieSessionFactory.class.php (121): Use of undefined constant COOKIE_PREFIX - assumed 'COOKIE_PREFIX'
error code: 0
file: /home/propalit/public_html/forum/wcf/lib/system/WCF.class.php (255)
php version: 5.2.17
wcf version: 1.0.7
date: Wed, 08 Feb 2012 12:49:53 +0000
request: /forum/
referer:

Stacktrace:

#0 /home/propalit/public_html/forum/wcf/lib/system/session/CookieSessionFactory.class.php(121): WCF::handleError(8, 'Use of undefine...', '/home/propalit/...', 121, Array)
#1 /home/propalit/public_html/forum/wcf/lib/system/session/SessionFactory.class.php(61): CookieSessionFactory->readSessionID()
#2 /home/propalit/public_html/forum/lib/system/WBBCore.class.php(201): SessionFactory->get()
#3 /home/propalit/public_html/forum/wcf/lib/system/WCF.class.php(91): WBBCore->initSession()
#4 /home/propalit/public_html/forum/global.php(18): WCF->__construct()
#5 /home/propalit/public_html/forum/index.php(7): require_once('/home/propalit/...')
#6 {main}