I am getting an issue on Magento 2.2 when trying to create promotion rule. This error occurs sometimes and the error disappears if run Magento upgrade command. But it comes again sometime.
My team recently ran into this on
v2.3.1 of Magento Community, and it appears that you may have an attribute with an
attribute_model of type
Magento\Eav\Model\Entity\Attribute when the system is actually expecting type
For reference, you can check out the line of code where that error is being thrown. For me it's here: https://github.com/magento/magento2/blob/2.3.1/app/code/Magento/SalesRule/Model/Rule/Condition/Product.php#L70-L71
You'll see a comment on the type of what that variable is (expected to be):
/* @var $attribute \Magento\Catalog\Model\ResourceModel\Eav\Attribute */
Well, my solution was to update that
attribute_model value in the
eav_entity_type tables directly - you'll see some others have done this in the Magento issue linked to in Rafael's answer. After this, you'll want to make sure you run a reindex and clear cache. Hope that helps!
Just a note: if you continue to run into this issue, it may be the case that you have some code (maybe custom or a 3rd party module) that is adding/updating an attribute and setting that
It's a native issue, but you can try these options:
1 - Try disabling third-party extensions (e.g. Mgt_DeveloperToolbar).
2 - Try to refresh or disable the cache before.
3 - As a temporary fix you can do that:
Override the file
vendor/magento/module-rule/Model/Condition/Product/AbstractProduct.php override the method
Magento\Rule\Model\Condition\Product\AbstractProduct::loadAttributeOptions(), and change the line:
if (!$attribute->isAllowedForRuleCondition() || !$attribute->getDataUsingMethod($this->_isUsedForRuleProperty))
if (!$attribute->getDataUsingMethod($this->_isUsedForRuleProperty) ||!$attribute->isAllowedForRuleCondition())