Terminal Service Plus

Hi,
I renew my licence/supporte and I've this message from TSPLUS:
WARNING: DO NOT ACTIVATE your support.lic file if your TSplus version is LOWER THAN 8.20, IT WOULD CRASH YOUR SERVER.

Soo I can't upgrade the server because it need a valid licence, but I can give him the valid licence because I'm in the 8.10 .
How con I solve this?
Miguel
PS: I've opened a ticket

Hello,

You will receive from us an Update Code which will allow you to update to 8.20, then you will be able to use the support.lic file you received from us following this procedure : terminalserviceplus.com/docs/activating-your-support
I can easily understand that this may seem a bit complicated as we are changing our update feature, however you should never have to need an update code for updating to the latest release after this.