If you use WP Staging Pro with its license key activated on the production site and you try to activate the license key another time on the staging site as well, it’s likely that you get an error message like the one below:
You see this message because you’ve already activated the license key on one of your sites. The license key can only be activated on one site at the same time when you’ve purchased the single site license. Let me explain why this is not an issue for you.
If you get this message on the staging site you can ignore it because you do not need to activate the license key on the staging site due to the fact that all the push and cloning operations are done from the plugin which is installed on the live site.
It’s more important to activate the plugin on the live site to make sure that WP Staging Pro on the production website is up to date.
If you already activated the license key on the staging site, just deactivate it there and then activate it on the live site again. That’s it.