On my Live Preview Page is a Link that redirects to my WP demo page what is on the same domain. But in the Developer Console shows up a message like this :
Refused to display 'http://crodev.net/wpdemo/wp-admin/admin.php?page=cteditor' in a frame because it set 'X-Frame-Options' to 'SAMEORIGIN'.
Dont understand why, because its on the same domain like the Preview Page.