Just upgraded to 220.127.116.11 and am getting this error when trying to view the customer grid in the backend.
I tried replacing:
With a fresh copy with no luck!
Fatal error: Call to a member function getBackend() on a non-object in /var/www/vhosts/MYSITE/app/code/core/Mage/Eav/Model/Entity/Collection/Abstract.php on line 514
Having a real headache trying to fix this error.