The error "you do not have the license to use this product" message is often seen when you try to register a license with the wrong product, for example trying to register a 4D Server license from the Singleuser runtime environment (the license registers but the error is presented because the license didnt grant access to the product you are using).

However, if you have confirmed that you are using the correct product for the license then it may be possible that that there is a problem saving the file to disk. For this i would suggest checking the /Library/Application Support/4D/Licenses folder. There has been an issue with updated macOS machines that include the old folder hierarchy from previous OS versions, essentially if the 4D folder is seen within the global Application Support folder 4D will try to use it, but the newest OS prevents access to that location. The solution is to remove the 4D folder from the global Application Support folder which then causes the application to use the Application Support folder within the current users home directory instead.

TL/DR;
1- make sure you are using the correct product that matches the license (4D or 4D Server)
2- remove the /Library/Application Support/4D folder (rename it to preserve the contents or delete)
3- try again