Twitter Cards Validation Server error, please try again


#1

I ’ m using the following url : http://t.co/hkRwySlbMD
I get the server error please try again message.
What i’m wronging??
I did all the attempts describe in other threads like robots.txt.
I used domain htpp and https and image hosted on my site and on external site.
It’s a simple html with the following structure: