If you receive the error 'This license key must be upgraded,' verify you are using the correct version of Parallels. Detailed solutions are provided in the Parallels Community Forums
If purchased through a reseller or the Parallels Online Store, the key is sent to the email address used during purchase. parallels desktop 18 activation key 30 characters
Buying Parallels Desktop from the official website or an authorized reseller ensures you get a legitimate activation key. If you receive the error 'This license key