My previous license is accepted, everything goes fine until your system tries to validate my CC... and then, it fails. I have already tried several times to place the order but it fails with a useless "something went wrong" error message.
Welcome to the Magix user to user forums, so not a contact for any Magix staff and it is not our system.
You need to email infoservice@magix.net and ask for their help.
The most common reason for payment failure is because all transactions involving EU companies (Magix is based in Germany) must use the 3d Secure transaction protocol. It is possible your bank/credit card issuer has not responded correctly to this check and so the transaction cannot be completed.