It may be for multiple reasons, but if the issue was due to the use of a particular card, it may be due to a restriction imposed by PayPal security. For example, if the card You used is not normally used in that manner, or if it was used more frequently than is normal in a set amount of time. That would trigger an alert or alarm for the card. In that case You can also pay directly through PayPal, via the PayPal Pro Express option. If you have any issue feel free to contact us and we will solve the issue and get You back to making music as quickly as possible!