When accessing the Facebook module (version 2.6.2) for Magento 1.9 it did not load and the screen was blank. When accessing the error log (var / log / facebook_product_feed_exception.log) I have identified the following exception:
facebook ERROR1: Call to a member function getId () on null @ /home//public_html/app/code/core/Mage/Catalog/Model/Product/Type/Configurable/Price.php