2.30 to 2.40 upgrade

After upgrading from 2.30 to 2.40 our customers are getting and error at checkout. I’t a message from the page saying that the payment information is not entered. And it still processes as if the payment was made. This has become a big problem, really need some help. This error is logged System.Exception: Payment information is not entered at Nop.Web.Controllers.CheckoutController.OpcConfirmOrder() in f:\Own\NopCommerce\Sources\src\Presentation\Nop.Web\Controllers\CheckoutController.cs:line 1322

Ok now I have a question, if I revert back to 2.30 can I leave the database as is? I am away from the office and can’t look at the script; however I can change the ISS directory back to the previous.

I did see some things in 2.40 I would like to take advantage of, but that can wait.