Fatal error: Uncaught TypeError: Argument 1 passed to Netzarbeiter_GroupsCatalog_Helper_Data::addGroupsFilterToProductCollection() must be an instance of Mage_Catalog_Model_Resource_Eav_Mysql4_Product_Collection, instance of Mage_Catalog_Model_Resource_Product_Collection given, called in /home/hempadmin/public_html/mag/app/code/community/Netzarbeiter/GroupsCatalog/Model/Catalog/Layer.php on line 37 and defined in /home/hempadmin/public_html/mag/app/code/community/Netzarbeiter/GroupsCatalog/Helper/Data.php:475 Stack trace: #0 /home/hempadmin/public_html/mag/app/code/community/Netzarbeiter/GroupsCatalog/Model/Catalog/Layer.php(37): Netzarbeiter_GroupsCatalog_Helper_Data->addGroupsFilterToProductCollection(Object(Mage_Catalog_Model_Resource_Product_Collection)) #1 /home/hempadmin/public_html/mag/app/code/core/Mage/Catalog/Model/Layer.php(103): Netzarbeiter_GroupsCatalog_Model_Catalog_Layer->prepareProductCollection(Object(Mage_Catalog_Model_Resource_Product_Collection)) #2 /home/hempadmin/public_html/mag/app/code/core/Mage/C in /home/hempadmin/public_html/mag/app/code/community/Netzarbeiter/GroupsCatalog/Helper/Data.php on line 475