When I tried to install and activate Parallels 13 from Parallels 12 on the same machine, I came to a screen that "Activates Parallels Desktop" with a filled out license (which looks like the one that I have for my subscription) and asks me to confirm. When I copy and paste the license from my subscription, I get "the product key of a previous version of Parallels Desktop has been not accepted on the license server." How can I resolve this ? I felt ignored. I tweeted, I sent Facebook message and I post in the community. I was able to get someone on Facebook Messenger...showed them the activation screen on 8/24. He figured out that all I had on my account is a upgrade license (I have been doing a subscription since 2015) and the only original full license that I had was back to version 7 with upgrades after that. He said that there needed to be an internal discussion and then would get back with me. I was given a parallels licence via messenger on 8/25 and I am now activated.