Fatal error after changing robot.txt setting

Question

Working on Magento 2.1.8 and PHP 7. I have changed in Admin Panel

Stores -> Configuration -> Catalog -> XMLSitemap -> Search Engine Submission Settings the value of "Enable Submission to Robots.txt" to Yes.

Following error message I got:

Fatal error: Class Zend\Stdlib\ArrayObject contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (IteratorAggregate::getIterator) in C:\xampp\htdocs\pferd\vendor\zendframework\zend-stdlib\src\ArrayObject.php on line 22

Following the beginning of file ArrayObject.php

namespace Zend\Stdlib;

use ArrayAccess;
use Countable;
use IteratorAggregate;
use Serializable;


 **line 22** class ArrayObject implements IteratorAggregate, ArrayAccess, Serializable, Countable

How can I reverse the change? I have no access anymore to AdminPanel to reverse the change. Thanks

Answer 1

Solution: To solve this problem, run following commands.

1. Delete the var directory from your root directory
2. php bin/Magento setup:upgrade
3. php bin/Magento setup:static-content:deploy
4. php bin/Magento cache:clean
5. php bin/Magento cache:flush

At the End stop apache and MySQL service and restart both services again which fixed your problem and everything works perfectly then.