There are 2 licenses under my account and 1 of them cannot be activated.
Hi @ARTTA , and welcome to our Forum.
Whenever you experience any issues with your license please kindly reach out to our dedicated support team as detailed here:
How do I contact Support? - News & FAQ - Enscape Community Forum
You can simply either share the e-mail used to acquire Enscape or the licensing key itself which needs a reset.
In the future and generally kindly also make sure to remove your license key before activating it another machine as detailed here.