It’s not an issue with Envato, it’s actually an issue with your server:
Refused to display ‘http://revis.payo-themes.com/’ in a frame because it set ‘X-Frame-Options’ to ‘sameorigin’.
The relevant headers sent back by your server are below - you can find these in the Network tab of your browser’s developer tools:
SAMEORIGIN means other websites, including ThemeForest, cannot embed your site in a frame. You need to either remove this header, or set it to something like:
X-Frame-Options: ALLOW-FROM http://preview.themeforest.net/