Fatal error: Uncaught Error: Call to undefined method Magento\Catalog\Model\Product\Type\Simple::getUsedProducts() in /var/www/html/app/code/Linets/RetailRocket/Helper/HelperProduct.php:64 Stack trace: #0 /var/www/html/app/code/Linets/RetailRocket/Block/ProductDetail.php(43): Linets\RetailRocket\Helper\HelperProduct->getChildrenSku(Object(Magento\Catalog\Model\Product\Interceptor)) #1 /var/www/html/app/code/Linets/RetailRocket/view/frontend/templates/product/view/product-retail-rocket.phtml(12): Linets\RetailRocket\Block\ProductDetail->getChildrenSku(Object(Magento\Catalog\Model\Product\Interceptor)) #2 /var/www/html/vendor/magento/framework/View/TemplateEngine/Php.php(59): include('/var/www/html/a...') #3 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(58): Magento\Framework\View\TemplateEngine\Php->render(Object(Linets\RetailRocket\Block\ProductDetail), '/var/www/html/a...', Array) #4 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(138): Magento\Framework\View\TemplateEngine\Php\I in /var/www/html/app/code/Linets/RetailRocket/Helper/HelperProduct.php on line 64