@Dledge Is your version available here?

https://www.magix.com/us/support/pro-audio-downloads/

Did you register it under another email? That would explain why it isn't visible. The problem is, you cannot activate it with a new email address. You first need to change the email address in your customer account. If the software isn't listed there you'll get error 24 during activation. In that case, only customer support at infoservice@magix.net can transfer licenses between different email accounts.