old activation code can't be accept by server parallels desktop

[MichaelZ11]

My permanent activation code is no longer usable. I got the activation key from the official website, why doesn't it work?
I'm installing a new PD in my new MacBook air. When I active PD with PD18 upgrade key, the software ask me to put the old key in. I type my PD16 pr key in, the software still pop-up window showing activation code can't be accept by server.
Please help me, thx

 

[MichaelZ11]

update the error screenshot

 

[Avinash Bundhoo]

update the error screenshot

Hello,
Thank you for reaching out.
We have reset the confirmation limit for the old key.
Please retry and let us know.
Thanks