After Updating to M2ePro 6.6.0 (Magento 18.104.22.168) we are not able to generate credit memos. In the error logs I can see, that there is a problem with loading several models via Mage::getModel.
PHP message: PHP Fatal error: Uncaught Error: Call to a member function handle() on boolean in /app/code/community/Ess/M2ePro/Observer/Creditmemo.php:47
The Model Ess_M2ePro_Model_Amazon_Order_Creditmemo_Handler can not be instantiated. In the file config.xml there is a part where the models are defined and it seems due to this change the models can not be created.
<!-- Observer dir. was moved outside of Model dir. -->
Is anybody facing the same issues after the update?