Got Sound Forge with Magix Music maker premium and get an error 14 when trying to activate program.
Sound Forge would have a different serial code than MM. Check you junk or spam mail folders.
Otherwise contact the Magix Customer Service which handles activation issues and such.
If you need help requesting a support ticked, see this comment:
https://www.magix.info/us/forum/wrong-serial-number--1259553/#ca1608151
btw. welcome to the Magix Sound Forge forum @Richarde-Schwahn. This is a users forum and no one here, including the moderators, has access to Magix products serial numbers and customer info.