How to migrate Magento Enterprise Version 2.1.8 to Magento Community Version 2.1.8?

I have installed a fresh copy of Magento CE with new database then Transfered the theme and the extensions.

Everything works fine.

Then I changed the database connection to the EE database. When I view a product and go to checkout/Cart, I got the below error:

Fatal error: Class 'Magento\GiftCard\Model\Attribute\Backend\Giftcard\Amount' not found in /home/user/public_html/vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php on line 93

Knowing that I have disabled all the GiftCard Extensions on the EE version before migration.