The following errors occurred: Invalid Payment Method Selection

[gei]

When a new or old client - with no payment methods on file - attempts to pay an invoice, they get the following error:

The following errors occurred:
Invalid Payment Method Selection

This error *only* occurs when they set the "save my credit card details" option to "no". When they set the option to "yes" (ie save the credit card), then they payment goes through fine. If they pay with an existing credit card on file it also works fine.

We are using the default invoice payment template (from six) with no changes. We are using our own credit card payment module. Any ideas what could be causing this? Is this a bug?

[gei]

FYI this has been acknowledged as a bug, CORE-14191, which should be fixed in the next release.

Considering the severity of this issue (like the last few payment-related issues we have posted), I'm surprised it has gone unnoticed...