The upgraded license does not work with my present version of Mellel
There are usually two types of problems with licenses:
A. The User Name or the Registration Code are not typed correctly. To remedy this, it is advisable to simply copy and paste the User Name and the Registration Code as they appear in the registration note.
B. People who've purchased an upgrade sometimes mistake their own older code, entered while purchasing the upgrade, for the new one, which appears a few lines below it.
It's worth to take note, when purchasing an upgrade, that the line "Keyword: registrationcodeupdate - XXXX-XXXX-XXXX-XXXX" is actually your old code, not the new one.