Fatal error: Uncaught TypeError: Argument 1 passed to Magento\Catalog\Model\ProductRepository::prepareSku() must be of the type string, null given, called in /home/zenpromo/public_html/vendor/magento/module-catalog/Model/ProductRepository.php on line 675 and defined in /home/zenpromo/public_html/vendor/magento/module-catalog/Model/ProductRepository.php:685 Stack trace: #0 /home/zenpromo/public_html/vendor/magento/module-catalog/Model/ProductRepository.php(675): Magento\Catalog\Model\ProductRepository->prepareSku(NULL) #1 /home/zenpromo/public_html/vendor/magento/module-catalog/Model/ProductRepository.php(308): Magento\Catalog\Model\ProductRepository->saveProductInLocalCache(Object(Magento\Catalog\Model\Product\Interceptor), '70f219631131d9b...') #2 /home/zenpromo/public_html/vendor/magento/module-catalog/Model/ProductRepository.php(273): Magento\Catalog\Model\ProductRepository->cacheProduct('70f219631131d9b...', Object(Magento\Catalog\Model\Product\Interceptor)) #3 /home/zenpromo/public_html/generated/code/Magento/Catalog in /home/zenpromo/public_html/vendor/magento/module-catalog/Model/ProductRepository.php on line 685