The other threads did not seem to cover my situation. Since posting exact errors and codes has been requested in the past, I figured I'd do so here.

I get this error every time I attempt to book a new flight using one of my saved credit cards. The CC's I have stored are valid and have valid expiration dates. I have the physical cards with me and know I'm using the right security codes. It's been occurring for 2-3 weeks straight now. I've bought several tickets in that timespan and it's happened every time. All normal new bookings, no exchanges of TTF's involved.

Fortunately, after I get the error, I can still go manually type in the credit card (the identical number to the one that generated the error) and buy the ticket. This error is a nuisance, but it hasn't prevented any actual bookings (yet...knock on wood).

Any ideas what's causing it?

Thanks!!