Call to a member function getBackend() on a non-object

Question

Client is trying to setup promotions via the admin but when saving and applying the promotion the server logs the following error (admin return blank screen):

PHP Fatal error: Call to a member function getBackend() on a non-object in /app/code/core/Mage/Catalog/Model/Resource/Product/Collection.php on line 855

Unable to find any info regarding this type of error, what may be causing it, or how to correct it.

Thanks for your help!

Answer 1

Use the following script to list product attributes with non-existant backend models:

umask(0);
require 'app/Mage.php';    
Mage::setIsDeveloperMode(true);
Mage::app('admin');

$entityType = Mage::getSingleton('eav/config')->getEntityType('catalog_product');
foreach ($entityType->getAttributeCollection() as $attribute) {
    if ($backendClass = $attribute->getBackendModel()) {
        try {
            class_exists(Mage::getConfig()->getModelClassName($backendClass), true);
        } catch (Exception $e) {
            echo "Not found the backend model {$backendClass} for product attribute {$attribute->getAttributeCode()}\n";
        }
    }
}