Unable to validate serial for upgrade to V13

[Vladimir Biryukov]

I have same problem (Nitro 12.16.9.574) but i can't validate for the upgrade - i get error message 

But i do not even know if i am legible or not

Quote

We were unable to validate your serial number. Please ensure you entered it correctly. If you believe you are eligible for an upgrade, please leave a post on our Community Forum and update us with your issue.

 

Edited February 26, 2021 by Vladimir Biryukov
addition

[Allain Umailin]

Hello @Vladimir Biryukov,

Thank you for reaching out to us through our Community Forums!

Please allow us to make necessary adjustments on your account so our Upgrade Portal will allow you to upgrade.

We will keep you posted once it is done.

Thank you for your patience.

[Allain Umailin]

Hello @Vladimir Biryukov,

Thank you for reaching out to us through our Community Forums!

I am pleased to inform you that a few adjustments has been made to your account records so please try upgrading again to version 13 with a discounted rate.

Thank you for choosing Nitro and I hope this helps.