Object at URL of type is invalid because a required property of type 'string' was not provided

Object at URL of type is invalid because a required property of type
'string' was not provided

Lately, when I use open graph to post an update to facebook I having this
issue "Object at URL 'http://gallery.mobile9.com/f/3536031/' of type
'social-mobilenine:file' is invalid because a required property
'social-mobilenine:file' of type 'string' was not provided."
I checked my meta in the url and it is
<meta content="social-mobilenine:file" property="og:type">
Any idea?