If you have updated to Avada 7.3 and have not yet re-registered your Avada website with a purchase code as explained in this help file, the Envato token key will only continue to be valid for an additional ten (10) days.
Once the ten (10) days are concluded, the Envato token key will be rendered invalid. This will not cause your site to break or to stop functioning normally. However, you will be required to register the website with a purchase code.
