Fatal error: PHP warning in file /home/woltlab/demo/forum2/wcf/lib/system/event/EventHandler.class.php (73): get_class() expects parameter 1 to be object, string given

Information:

error message: PHP warning in file /home/woltlab/demo/forum2/wcf/lib/system/event/EventHandler.class.php (73): get_class() expects parameter 1 to be object, string given
error code: 0
file: /home/woltlab/demo/forum2/wcf/lib/system/WCF.class.php (255)
php version: 5.4.45
wcf version: 1.0.10 (Horizon)
date: Sat, 05 Jul 2025 20:38:53 +0000
request: /forum2/index.php?page=UsersOnline&s=619b1e07f4c666c327c3b09b4e12dc10399130e6
referer:

Stacktrace:

#0 [internal function]: WCF::handleError(2, 'get_class() exp...', '/home/woltlab/d...', 73, Array)
#1 /home/woltlab/demo/forum2/wcf/lib/system/event/EventHandler.class.php(73): get_class('UserAuth')
#2 /home/woltlab/demo/forum2/wcf/lib/system/event/EventHandler.class.php(142): EventHandler::executeInheritedActions('UserAuth', 'loadInstance', 'UserAuth', 'loadInstance@Us...')
#3 /home/woltlab/demo/forum2/wcf/lib/system/auth/UserAuth.class.php(28): EventHandler::fireAction('UserAuth', 'loadInstance')
#4 /home/woltlab/demo/forum2/wcf/lib/system/session/CookieSessionFactory.class.php(34): UserAuth::getInstance()
#5 /home/woltlab/demo/forum2/wcf/lib/system/session/SessionFactory.class.php(71): CookieSessionFactory->create()
#6 /home/woltlab/demo/forum2/lib/system/WBBCore.class.php(201): SessionFactory->get()
#7 /home/woltlab/demo/forum2/wcf/lib/system/WCF.class.php(91): WBBCore->initSession()
#8 /home/woltlab/demo/forum2/global.php(18): WCF->__construct()
#9 /home/woltlab/demo/forum2/index.php(7): require_once('/home/woltlab/d...')
#10 {main}