Notice: Undefined property: DOMDocument::$documentElement in /var/www/vhosts/theswitchers.org/toolbox.theswitchers.org/httpdocs/vendor/symfony/dependency-injection/Loader/XmlFileLoader.php on line 590

Fatal error: Uncaught Error: Call to a member function getAttributeNS() on null in /var/www/vhosts/theswitchers.org/toolbox.theswitchers.org/httpdocs/vendor/symfony/dependency-injection/Loader/XmlFileLoader.php:590 Stack trace: #0 /var/www/vhosts/theswitchers.org/toolbox.theswitchers.org/httpdocs/vendor/symfony/config/Util/XmlUtils.php(89): Symfony\Component\DependencyInjection\Loader\XmlFileLoader->validateSchema(Object(DOMDocument), false) #1 /var/www/vhosts/theswitchers.org/toolbox.theswitchers.org/httpdocs/vendor/symfony/config/Util/XmlUtils.php(146): Symfony\Component\Config\Util\XmlUtils::parse('<?xml version="...', Array) #2 /var/www/vhosts/theswitchers.org/toolbox.theswitchers.org/httpdocs/vendor/symfony/dependency-injection/Loader/XmlFileLoader.php(397): Symfony\Component\Config\Util\XmlUtils::loadFile('/var/www/vhosts...', Array) #3 /var/www/vhosts/theswitchers.org/toolbox.theswitchers.org/httpdocs/vendor/symfony/dependency-injection/Loader/XmlFileLoader.php(49): Symfony\Component\DependencyInjection\Loader\XmlF in /var/www/vhosts/theswitchers.org/toolbox.theswitchers.org/httpdocs/vendor/symfony/dependency-injection/Loader/XmlFileLoader.php on line 590