macOS High Sierra - Upgrade from pd11 to pd13 after fresh OS install

I'm a little bit confused about the proper procedure for upgrading from pd11 to pd13 on a brand new macOS high sierra system.
This is a fresh install of a system where I was running pd11 before. after fresh OS upgrade I installed pd13 but I can't use the pd11 key. so, I re-installed pd11 just to enter the key, hoping I can then upgrade to pd13. but, upon trying to activate pd11 I get an error message "reached max number of activations"!? what the heck!? this is my only machine and now I can't run pd11 or pd13.
I logged into my parallels account I can see under licenses PD11 1 computer but I can't unregister it from there.
Is there a way to install pd13 directly after fresh os install and somehow enter pd11+pd13 upgrade keys?

Any help would be appreciated.

 

Hello @CatalinT , we have made necessary changes to the activation key for version 13, please reattempt activation and check if it works and then follows the steps provided at http://kb.parallels.com/124250 to upgrade to version 13.
Thanks