TYPO3 Core

(1/1) Error
Typed property TYPO3\CMS\Core\Authentication\AbstractUserAuthentication::$userSession must not be accessed before initialization

in /home/ben/src/TYPO3.CMS/typo3/sysext/core/Classes/Authentication/AbstractUserAuthentication.php line 1012
     * @return mixed
     */
    public function getSessionData($key)
    {
        return $this->userSession->get($key);
    }