Why Is My License Key Invalid?
If you're getting the "You do not have a valid license" message for your theme, then the first thing you should do it check if you have the latest version of the theme. How do you do that?
Go to Appearance -> Themes and click on the installed Themes Details and next to the themes name is the version of it.
Another way you can do this is to search the version in the style.css file of your theme.
The next step is to check what is the last version of the theme you are using and the best way to do that is to go to your Purchase History and see the version number beneath the themes name.
In case you've downloaded the theme from wordpress.org, you can check the version of the theme by accessing the themes page and click on the Preview button.
If the version of the theme you have is not the last one then update to the latest version and you will no longer have the invalid license issue.
How do you update to the latest version?
For doing the update there are 2 methods you can use:
1. You will start by downloading the theme, unzip it and overwrite the existing theme files through FTP. If you're using Filezilla make sure to check transfer type to binary.
2. The other method consists in deleting the old version of the theme from the Dashboard and upload the .zip file of the one that you just download it.