Braintree: 2015 Transaction Not Allowed

What This Means

From Braintree:
Error 2015: The customer's bank is declining the transaction for unspecified reasons, possibly due to an issue with the card itself. They will need to contact their bank or use a different payment method.

Suggested Next Steps

Contact the customer to have them add a new payment method and add it to their Scheduled Order.
You may also choose to add a new payment method for your customer, see "Adding a New Payment Method for Your Customer" below.
Once a new payment method is added to the Scheduled Order, the Scheduled Order should be processed with the new payment method.

Adding A New Payment Method for Your Customer?

If you are adding a new payment method for your customer directly to your payment gateway (manually), ensure that you edit the failed Scheduled Order, add a new payment method, and copy the required billing information directly to their Scheduled Order including:

Gateway CustomerId
Gateway PaymentId
Billing Address
Payment Method Description (optional, but strongly suggested because it is used to display the payment method to your customer)

After Resolving the Issue

Once this issue is resolved, you should use the action to Restart Processing the Failed Scheduled Order.