Magento – Fatal error: Call to a member function setMessageBody() on a non-object

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";
        }
    }
}

I had this same problem while installing an instance of Magento within our testing environment. Because I downloaded Magento Enterprise on my local machine and pushed the code to the test environment using GIT, my .gitignore file left out the enterprise.xml and config.xml. Because these files were missing it generated the error message described by the OP. Once in place, it sent me to the Magento Install page! Hope that helps someone out there.