Fatal error: Uncaught TypeError: JTL\Shop::setLanguage(): Argument #1 ($languageID) must be of type int, null given, called in /var/www/virtual/lassners-schulzeit.de/htdocs/includes/src/Session/Frontend.php on line 321 and defined in /var/www/virtual/lassners-schulzeit.de/htdocs/includes/src/Shop.php:355 Stack trace: #0 /var/www/virtual/lassners-schulzeit.de/htdocs/includes/src/Session/Frontend.php(321): JTL\Shop::setLanguage() #1 /var/www/virtual/lassners-schulzeit.de/htdocs/includes/src/Session/Frontend.php(117): JTL\Session\Frontend->updateGlobals() #2 /var/www/virtual/lassners-schulzeit.de/htdocs/includes/src/Session/Frontend.php(75): JTL\Session\Frontend->setStandardSessionVars() #3 /var/www/virtual/lassners-schulzeit.de/htdocs/includes/src/Session/Frontend.php(61): JTL\Session\Frontend->__construct() #4 /var/www/virtual/lassners-schulzeit.de/htdocs/includes/globalinclude.php(96): JTL\Session\Frontend::getInstance() #5 /var/www/virtual/lassners-schulzeit.de/htdocs/index.php(5): require('...') #6 {main} thrown in /var/www/virtual/lassners-schulzeit.de/htdocs/includes/src/Shop.php on line 355