Fatal error: Uncaught Error: Call to a member function isStatic() on boolean in /home/users/stage_mgprojekt/public_html/magento_production/app/code/core/Mage/Eav/Model/Entity/Collection/Abstract.php:430 Stack trace: #0 /home/users/stage_mgprojekt/public_html/magento_production/app/code/core/Mage/Catalog/Model/Resource/Product/Collection.php(517): Mage_Eav_Model_Entity_Collection_Abstract->addAttributeToSelect('id', 'name') #1 /home/users/stage_mgprojekt/public_html/magento_production/app/code/local/Mgp/Frontend/Helper/Product.php(104): Mage_Catalog_Model_Resource_Product_Collection->addAttributeToSelect('id', 'name') #2 /home/users/stage_mgprojekt/public_html/magento_production/app/code/local/Mgp/Frontend/Helper/Product.php(30): Mgp_Frontend_Helper_Product->getCategoryProductsByName(Object(Mage_Catalog_Model_Category)) #3 /home/users/stage_mgprojekt/public_html/magento_production/app/design/frontend/mgp/default/template/catalog/product/view/navigation.phtml(2): Mgp_Frontend_Helper_Product->getNeighbourProduct() #4 /home/u in /home/users/stage_mgprojekt/public_html/magento_production/app/code/core/Mage/Eav/Model/Entity/Collection/Abstract.php on line 430