@Nate311 We’re passing along the message that Stripe got from your credit card company. Other sites might check this security code at different times, so it’s possible your card might be working somewhere else while it’s getting rejected here. One possibility is that you’ve gotten a new card (with a new security code) but you’re looking at the old one.
It’s also possible there’s something else wrong with your card, but the message they’re sending is just the generic “security code” error. You’ll need to call the number on the back of the card to see if they can help.