You have Registration Connection error.
It means there isn't way to connect to http://update.gt3themes.com/
from your server end to register the theme at our source.
To verify your purchase code your WordPress (located on your hosting) has to connect to our server, but there is no connection, even an attempt.
Please contact you hosting support and ask why there isn't way to connect to http://update.gt3themes.com/
from their server.
Maybe there are some restrictions for outbound requests. The request from your server isn't coming.