I had created an application that was meant to be displayed in a frame loaded from another url. There were issues with the frame not loading properly and using developer tools the console displayed the error:
Refused to display '...' in a frame because it set 'X-Frame-Options' to 'SAMEORIGIN'
The fix to this was to add :
AntiForgeryConfig.SuppressXFrameOptionsHeader = true;
to the Application_Start function in Global.asax. You must also add:
to get access to that.