Fatal error: Uncaught TypeError: Argument 1 passed to Mage_Catalog_Model_Resource_Product_Collection::addCategoryFilter() must be an instance of Mage_Catalog_Model_Category, null given, called in /home/vollmax/public_html/app/design/frontend/ultimo/vollmax/template/catalog/product/list/upsell.phtml on line 182 and defined in /home/vollmax/public_html/app/code/core/Mage/Catalog/Model/Resource/Product/Collection.php:717 Stack trace: #0 /home/vollmax/public_html/app/design/frontend/ultimo/vollmax/template/catalog/product/list/upsell.phtml(182): Mage_Catalog_Model_Resource_Product_Collection->addCategoryFilter(NULL) #1 /home/vollmax/public_html/app/code/core/Mage/Core/Block/Template.php(241): include('/home/vollmax/p...') #2 /home/vollmax/public_html/app/code/core/Mage/Core/Block/Template.php(272): Mage_Core_Block_Template->fetchView('frontend/ultimo...') #3 /home/vollmax/public_html/app/code/core/Mage/Core/Block/Template.php(286): Mage_Core_Block_Template->renderView() #4 /home/vollmax/public_html/app/code/core/Mage/Core/Blo in /home/vollmax/public_html/app/code/core/Mage/Catalog/Model/Resource/Product/Collection.php on line 717