Argument 1 passed to Magento\Authorizenet\Model\Directpost\Request::__construct() must be an instance of Magento\Framework\Intl\DateTimeFactory
This error is getting displayed when I am clicking on the place order button in Magento2.
I had the same problem which happened after Auth.net phased out MD5 based transHash in favor of SHA-512. To fix, I replaced these two files -
with the following files