Fatal error: Uncaught Error: Class "Symfony\Component\CssSelector\Node\AbstractNode" not found in C:\WebServer\htdocs\bookshelf\vendor\symfony\css-selector\Node\FunctionNode.php:26 Stack trace: #0 {main} thrown in C:\WebServer\htdocs\bookshelf\vendor\symfony\css-selector\Node\FunctionNode.php on line 26