Notice: Undefined property: DOMDocument::$documentElement in /home/www/palmenmarkt.de/vendor/symfony/dependency-injection/Loader/XmlFileLoader.php on line 590

Fatal error: Uncaught Error: Call to a member function getAttributeNS() on null in /home/www/palmenmarkt.de/vendor/symfony/dependency-injection/Loader/XmlFileLoader.php:590 Stack trace: #0 /home/www/palmenmarkt.de/vendor/symfony/config/Util/XmlUtils.php(89): Symfony\Component\DependencyInjection\Loader\XmlFileLoader->validateSchema(Object(DOMDocument), false) #1 /home/www/palmenmarkt.de/vendor/symfony/config/Util/XmlUtils.php(146): Symfony\Component\Config\Util\XmlUtils::parse('<?xml version="...', Array) #2 /home/www/palmenmarkt.de/vendor/symfony/dependency-injection/Loader/XmlFileLoader.php(397): Symfony\Component\Config\Util\XmlUtils::loadFile('/home/www/palme...', Array) #3 /home/www/palmenmarkt.de/vendor/symfony/dependency-injection/Loader/XmlFileLoader.php(49): Symfony\Component\DependencyInjection\Loader\XmlFileLoader->parseFileToDOM('/home/www/palme...') #4 /home/www/palmenmarkt.de/engine/Shopware/Kernel.php(653): Symfony\Component\DependencyInjection\Loader\XmlFileLoader->load('services.xml') #5 /home/www/palmenm in /home/www/palmenmarkt.de/vendor/symfony/dependency-injection/Loader/XmlFileLoader.php on line 590