cambio el metodo por prop.

Services/TaskLoggerService.php

@@ -38,7 +38,7 @@ class TaskLoggerService implements ConsumerInterface
      */
     public function execute(AMQPMessage $msg)
     {
-        $msgBody = unserialize($msg->getBody());
+        $msgBody = unserialize($msg->body);
         if (isset($msgBody['id']) && isset($msgBody['content'])) {
             $taskloggerId = $msgBody['id'];
             $content = $msgBody['content'];