Fatal error: PHP notice in file /var/www/web1/html/boards/QuasselForumAllerleiSims3/wcf/lib/system/session/CookieSessionFactory.class.php (121): Use of undefined constant COOKIE_PREFIX - assumed 'COOKIE_PREFIX'

Information:

error message: PHP notice in file /var/www/web1/html/boards/QuasselForumAllerleiSims3/wcf/lib/system/session/CookieSessionFactory.class.php (121): Use of undefined constant COOKIE_PREFIX - assumed 'COOKIE_PREFIX'
error code: 0
file: /var/www/web1/html/boards/QuasselForumAllerleiSims3/wcf/lib/system/WCF.class.php (255)
php version: 5.3.29
wcf version: 1.0.11 pl 1 (Horizon)
date: Sun, 22 Oct 2017 08:24:02 +0000
request: /boards/QuasselForumAllerleiSims3/index.php?page=DownloadDB
referer:

Stacktrace:

#0 /var/www/web1/html/boards/QuasselForumAllerleiSims3/wcf/lib/system/session/CookieSessionFactory.class.php(121): WCF::handleError(8, 'Use of undefine...', '/var/www/web1/h...', 121, Array)
#1 /var/www/web1/html/boards/QuasselForumAllerleiSims3/wcf/lib/system/session/SessionFactory.class.php(61): CookieSessionFactory->readSessionID()
#2 /var/www/web1/html/boards/QuasselForumAllerleiSims3/lib/system/WBBCore.class.php(170): SessionFactory->get()
#3 /var/www/web1/html/boards/QuasselForumAllerleiSims3/wcf/lib/system/WCF.class.php(91): WBBCore->initSession()
#4 /var/www/web1/html/boards/QuasselForumAllerleiSims3/global.php(18): WCF->__construct()
#5 /var/www/web1/html/boards/QuasselForumAllerleiSims3/index.php(7): require_once('/var/www/web1/h...')
#6 {main}