If you see the error message "Checkout shopping cart failed" when creating labels, please check the following:
Does your login work in the Portokasse portal? Deutsche Post may temporarily lock your account if the password has been entered incorrectly too many times.
Does your Portokasse account have a sufficiently high balance to create the desired stamps/labels? If not, top up your balance and try again.
If the problem persists, please contact our support.