vendor/magento/module-sales/etc/events.xml

<event name="sales_order_save_after">     <observer name="sales_order_save_after" instance="Magento\Sales\Observer\SalesOrderSaveAfter" /> </event>  

vendor/magento/module-sales/Observer/SalesOrderSaveAfter.php

public function execute(\Magento\Framework\Event\Observer $  observer) {        $  ObserverInterface = $  observer->getEvent()->getOrder(); //Get customer object      if($  ObserverInterface->getId()){        echo $  ObserverInterface->getId()."<br>";     }      $  OldStatus=$  ObserverInterface->getOrigData('status');     $  NewStatus=$  ObserverInterface->getStatus();     echo "OldStatus: ".$  OldStatus."<br>";     echo "NewStatus: ".$  NewStatus."<br>"; } 

Output

I am trying to get order status in sales_order_save_after observer, In the output am getting the result but it showing an interceptor error. what it means? how can i solve this issue??. Thanks in advance for your valuabe answers.