[CentOS 7.6.1810 / Apache 2.4.6 / PHP 7.1.28 / Magento 2.3.1]
I have installed porto theme.But can't access product page.
Contents of error_log
[Thu Apr 25 18:10:10.335721 2019] [php7:error] [pid 31336] [client 122.20.150.30:60875] PHP Fatal error: Uncaught Error: Call to a member function getData() on null in /var/www/html/app/design/frontend/Smartwave/porto/Magento_Catalog/templates/product/view/details.phtml:18nStack trace:n#0 /var/www/html/vendor/magento/framework/View/TemplateEngine/Php.php(59): include()n#1 /var/www/html/vendor/magento/framework/View/Element/Template.php(271): Magento\Framework\View\TemplateEngine\Php->render(Object(Magento\Catalog\Block\Product\View\Details), '/var/www/html/a...', Array)n#2 /var/www/html/vendor/magento/framework/View/Element/Template.php(301): Magento\Framework\View\Element\Template->fetchView('/var/www/html/a...')n#3 /var/www/html/vendor/magento/framework/View/Element/AbstractBlock.php(668): Magento\Framework\View\Element\Template->_toHtml()n#4 /var/www/html/vendor/magento/framework/View/Layout.php(557): Magento\Framework\View\Element\AbstractBlock->toHtml()n#5 /var/www/html/vendor/magento/framework/View/Layout.php(533): Magento\Framework\View\Layout->_renderBlock('product.info.de...')n#6 /var/www/html/generated in /var/www/html/app/design/frontend/Smartwave/porto/Magento_Catalog/templates/product/view/details.phtml on line 18, referer: