Fatal error: Uncaught Error: Interface "Symfony\Component\EventDispatcher\EventDispatcherInterface" not found in C:\mywamp\sites\allsite\calcomposer\vendor\symfony\event-dispatcher\ImmutableEventDispatcher.php:19 Stack trace: #0 {main} thrown in C:\mywamp\sites\allsite\calcomposer\vendor\symfony\event-dispatcher\ImmutableEventDispatcher.php on line 19