Fatal error: Uncaught Error: Class 'Symfony\Component\Config\Definition\Builder\VariableNodeDefinition' not found in C:\xampp\htdocs\plugins\Symfony\Component\Config\Definition\Builder\ScalarNodeDefinition.php:21 Stack trace: #0 {main} thrown in C:\xampp\htdocs\plugins\Symfony\Component\Config\Definition\Builder\ScalarNodeDefinition.php on line 21