Fatal error: Uncaught TypeError: Return value of UlysseNardin\CustomProductListPage\Block\Catalog\Product\ListProduct::getIntroParagraph() must be of the type string, null returned in /var/www/html/app/code/UlysseNardin/CustomProductListPage/Block/Catalog/Product/ListProduct.php:244 Stack trace: #0 /var/www/html/app/code/UlysseNardin/CustomProductListPage/Block/Catalog/Product/ListProduct.php(104): UlysseNardin\CustomProductListPage\Block\Catalog\Product\ListProduct->getIntroParagraph() #1 /var/www/html/app/code/UlysseNardin/CustomProductListPage/Block/Catalog/Product/ListProduct.php(90): UlysseNardin\CustomProductListPage\Block\Catalog\Product\ListProduct->getAssignableData() #2 /var/www/html/vendor/magento/framework/View/Element/AbstractBlock.php(1094): UlysseNardin\CustomProductListPage\Block\Catalog\Product\ListProduct->_toHtml() #3 /var/www/html/vendor/magento/framework/View/Element/AbstractBlock.php(1098): Magento\Framework\View\Element\AbstractBlock->Magento\Framework\View\Element\{closure}() #4 /var/www/html/vendo in /var/www/html/app/code/UlysseNardin/CustomProductListPage/Block/Catalog/Product/ListProduct.php on line 244