Trying to update Magento 2.1.2 to 2.2.2. Having major issues. Tried updating via the admin area SYSTEM UPGRADE. Just hangs forever. Double checked the memory allocation with the host and it's set to 2GB confirmed by system readiness check.

Tried running composer update via SSH command line. That doesn't work. I get a memory allocation error but have confirmed with host that all is set to 2GB. Checked via php.ini and file that displays the memory allotment. I found that there was a different php.ini file that Magento loads. Asked host (SiteGround) to check and they fixed and updated that file.

Went through the process of downloading Magento 2.2.2 and overwritint the files that way. https://www.goivvy.com/blog/magento-2-upgrade Step 3. But after going through that process I now have a fatal error that displays on the frontend as well as the URL for the admin:

Fatal error: Uncaught Error: Cannot instantiate interface Magento\Framework\Serialize\SerializerInterface in /home/####/public_html/magento2/vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:50
Stack trace:
#0 /home/####/public_html/magento2/vendor/magento/framework/ObjectManager/ObjectManager.php(70): Magento\Framework\ObjectManager\Factory\Dynamic\Developer->create('Magento\\Framewo...')
#1 /home/####/public_html/magento2/vendor/magento/framework/ObjectManager/Config/Config.php(345): Magento\Framework\ObjectManager\ObjectManager->get('Magento\\Framewo...')
#2 /home/####/public_html/magento2/vendor/magento/framework/ObjectManager/Config/Config.php(276): Magento\Framework\ObjectManager\Config\Config->getSerializer()
#3 /home/####/public_html/magento2/vendor/magento/framework/ObjectManager/ObjectManager.php(84): Magento\Framework\ObjectManager\Config\Config->extend(Array)
#4 /home/####/public_html/magento2/vendor/magento/framework/App/ObjectManager/Environment/Developer.php(79): M in /home/####/public_html/magento2/vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php on line 50

There are no files in var/cache No more directory of var/generation or var/di. (completely gone)

I'm at a loss as how to fix this error. Any help is very much appreciated. I have a backup of the website so I could just revert it back to 2.1.2 but not sure how to proceed with updating.

  • Your var/generation folder is now move to the root in /generated, but that its empty. Feb 5, 2018 at 20:39
  • Thanks for your reply. I'm not sure what that means ;). Here's what I have in the generated:
    – girdy
    Feb 5, 2018 at 23:43
  • /magento2/generated/code/Magento/Framework/App/ResourceConnection/Proxy.php
    – girdy
    Feb 5, 2018 at 23:44
  • /magento2/generated/code/Magento/Backend/App/Request/PathInfoProcessor/Proxy.php
    – girdy
    Feb 5, 2018 at 23:45

1 Answer 1


Magento 2.2 utilizes serializer interface to convert data to JSON format: http://devdocs.magento.com/guides/v2.2/ext-best-practices/tutorials/serialized-to-json-data-upgrade.html The error implies the interface has failed.

memory_limit parameter should be increased in master php.ini file. Master file location can be found by issuing the following command:

php -i | grep 'Configuration File'

Web server should be restarted afterwards.

Update Magento code base with the help of composer:

composer require magento/product-community-edition 2.2.2 --no-update
composer update

This should cure the issue.

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