Fatal error: PHP notice in file /srv/www/vhosts/no-kill.de/httpdocs/lib/data/boxes/PollBox.class.php (24): Trying to access array offset on value of type bool

Information:

error message: PHP notice in file /srv/www/vhosts/no-kill.de/httpdocs/lib/data/boxes/PollBox.class.php (24): Trying to access array offset on value of type bool
error code: 0
file: /srv/www/vhosts/no-kill.de/httpdocs/wcf/lib/system/WCF.class.php (255)
php version: 7.4.7
wcf version: 1.0.11 pl 1 (Horizon)
date: Mon, 06 Jul 2020 11:06:53 +0000
request: /index.php?page=Portal&s=8d3e58b639e87a6bc0b813af0deeb5ee6acf8da6
referer:

Stacktrace:

#0 /srv/www/vhosts/no-kill.de/httpdocs/lib/data/boxes/PollBox.class.php(24): WCF::handleError(8, 'Trying to acces...', '/srv/www/vhosts...', 24, Array)
#1 /srv/www/vhosts/no-kill.de/httpdocs/lib/system/portalbox/PortalBoxFactory.class.php(47): PollBox->__construct(Array, 'poll')
#2 /srv/www/vhosts/no-kill.de/httpdocs/lib/system/portalbox/PortalBoxFactory.class.php(32): PortalBoxFactory->parseBoxData('type2', '9')
#3 /srv/www/vhosts/no-kill.de/httpdocs/lib/system/portalbox/PortalBoxFactory.class.php(8): PortalBoxFactory->makeBoxData()
#4 /srv/www/vhosts/no-kill.de/httpdocs/lib/page/PortalPage.class.php(42): PortalBoxFactory->__construct()
#5 /srv/www/vhosts/no-kill.de/httpdocs/lib/page/PortalPage.class.php(36): PortalPage::initPortalBox()
#6 /srv/www/vhosts/no-kill.de/httpdocs/lib/page/PortalPage.class.php(28): PortalPage::getPortalBoxes()
#7 /srv/www/vhosts/no-kill.de/httpdocs/wcf/lib/page/AbstractPage.class.php(77): PortalPage->assignVariables()
#8 /srv/www/vhosts/no-kill.de/httpdocs/wcf/lib/page/AbstractPage.class.php(36): AbstractPage->show()
#9 /srv/www/vhosts/no-kill.de/httpdocs/wcf/lib/util/RequestHandler.class.php(63): AbstractPage->__construct()
#10 /srv/www/vhosts/no-kill.de/httpdocs/wcf/lib/util/RequestHandler.class.php(91): RequestHandler->__construct('PortalPage', Array, 'page')
#11 /srv/www/vhosts/no-kill.de/httpdocs/index.php(8): RequestHandler::handle(Array)
#12 {main}