As the part of creating bundle product programmatically in Magento 2. I am getting below error. Even i removed var/cache and generation.

This may be a duplicate question but none of the answer is working for this issue.

Fatal error: Cannot instantiate interface Magento\Catalog\Api\Data\ProductExtensionInterface in \ObjectManager\Factory\Dynamic\Developer.php on line 73

Used below code as the reference of link

$productExtension = $objectManager->create(\Magento\Catalog\Api\Data\ProductExtensionInterface::class);
$option = $objectManager->create(\Magento\Bundle\Api\Data\OptionInterface::class);

I am using object manager for temporary/quick purpose, will convert the object manager to constructor injunction.

Any one can help me on this issue.

7 Answers 7


I think you have not mentioned the preference in your di.xml. I also faced the same issue when I was creating custom config xml file module.

I got the issue when I called this code:

$testConfig = $this->_objectManager->get('Training\Test\Model\Config\ConfigInterface');
$myNodeInfo = $testConfig->getMyNodeInfo();

Below is the sample code I have added in my di.xml, may be it may help you to get reference:

<preference for="Training\Test\Model\Config\ConfigInterface" type="Training\Test\Model\Config" />

Here I have implemented the interface in Training\Test\Model\Config class and my getMyNodeInfo() method is defined in that Model.

So based on the the preference defined in di.xml the code ->get('Training\Test\Model\Config\ConfigInterface'); will create an object of type Training\Test\Model\Config.

  • its worked for me, Dont user _objectManager
    – matinict
    Commented Jan 10, 2021 at 9:42

I struggled with this and then found a solution that worked for me in the documentation.

Be sure to add your interface as a preference (correctly) in the di.xml, and then run php bin/magento setup:di:compile.

  • 2
    My problem was that I placed the di.xml in the etc/frontend folder instead of the etc root by accident, but your answer led me to find that.
    – KyleBunga
    Commented May 2, 2019 at 17:30
  • ah thank you man.
    – Kevinzie
    Commented May 13 at 14:17

You should not use the ObjectManager.

Collect your dependencies via _constructor.

In case your interface still won't be loaded, check your di.xml and validate that a preference is available.

  • @ David Lambauer Even i used constructor i am getting Cannot instantiate interface Magento\Catalog\Api\Data\ProductExtensionInterface in magento\framework\ObjectManager\Factory\Dynamic\Developer.php on line 73 Commented Oct 13, 2016 at 10:15
  • 1
    Did you add the factory to your use statements? use Magento\Catalog\Api\Data\ProductExtensionInterfaceFactory; Commented Oct 13, 2016 at 11:24

I tried this mentioned in another thread but it didn't solve:

redis-cli flushall

Finally, got solved by running setup:upgrade:

bin/magento setup:upgrade

# also run, if in production mode
bin/magento setup:static-content:deploy
bin/magento setup:di:compile
  • 1
    I had the same problem locally by going to an old project version, the problem was related to the redis cache, I spent time on it because it's one of the things that we don't necessarily think about; those who use "warden" stack, the command to flush redis locally is: "warden redis flushall".it can help other people
    – PЯINCƎ
    Commented Jan 18 at 15:52

Please make sure module is enabled. You can verify using {{MagentoRoot}}/app/etc/config.php file. In my case module was disabled.


I have faced the similar issue i.e. cannot instantiate interface for some third party module.
The reason that I found out after debugging that the corresponding module's entry was missing from the app/etc/config.php but the module's code was present in the codebase.
After manually adding the module's entry in the app/etc/config.php file, the issue got resolved.

  • There is no such a file app/etc/config.xml in M2
    – medina
    Commented Jun 3, 2020 at 2:41
  • @medina it's config.php, I have updated my answer. Commented Jun 3, 2020 at 4:16
  • should be added using bin/magento set:up command
    – jim smith
    Commented Nov 15, 2023 at 17:46

If anyone meets this bug, you should check if you declare an inherence from the interface to the implemented class in di.xml with preference tag. Then run bin/magento setup:upgrade to remove var/generation and cache. For production, you also need to run:

bin/magento setup:static-content:deploy
bin/magento setup:di:compile

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