Hi, I just reset my Mac. And I tried to activate my Parallels. I owned a 12 version permanent serial key. I purchased the upgrade version permanent serial key (version 16), and when I try to activate version 16 , I get an error when I enter the 12 version key in the previous version serial request after entering the 16 version serial key. I hope you solve this problem. Parallels 12 version (permanent serial) The last serial number is 'xxxxxx-xxxxxx-xxxxxx-xxxxxx-TNCXNH'. Please comment if you need more information. Thanks for the help