You can encounter the following error when you try to log into the game account.
Error occurs if you forgot to do the main thing after you did the payment - you haven't activated the purchased package. To resolve this you need to locate the payment confirmation on your e-mail and click "Activate link". After this the package will be bound to your account. If you haven't received the payment confirmation - you can contact Xsolla. They will gladly help you and re-send the payment confirmation manually. You can reach them at help.xsolla.com.