If you have the single or business site license then there is a limit to the number of sites you can have active at a single time. This process is typically managed through the plugin itself by activating or deactivating the license in Projects > Settings. However, there are instances where you can become unable to deactivate the site in this manor, preventing you from activating the license on a different site.
This commonly occurs when someone redesigns their site and fails to deactivate their license before removing the plugin.
You can manually deactivate your site by logging into your account page on ProjectPanorama.com.
Once logged in, you’ll see a list of all your active licenses. Clicking on “view licenses” link will bring you to a page where you can choose to “manage sites.” From this page you can manually add or remove sites you’d like the license to be active on.