Og:image Iimage could not be processed... has invalid content type

I'm quite new to JFBConnect and I'm facing the problem that facebook does not show any image in the link.
I have tried several methods and I get different errors while debugging it on Facebook.
When choosing option "Article Intro Image", I get the error "The 'og:image' property should be explicitly provided, even if a value can be inferred from other tags."

I tried to use a custom image (first png then jpg) and i get the following errors: "Provided og:image URL, www.travel-video.info/images/logos/logo-carre-1024.jpg could not be processed as an image because it has an invalid content type."
Any suggestion...?

I'm not sure if this code is what you are looking for, but I can find the following in the sourde:

<script type="text/javascript">jfbc.login.logout_facebook = false;
jfbc.base = 'www.travel-video.info/';
jfbc.return_url = 'L25sL3ZpZGVvcy9tYWhlc2h3YXItaW5kaWEtbWFkaHlhLXByYWRlc2guaHRtbA==';
jfbc.login.scope = 'email';
jfbc.login.show_modal = '0';
jfbc.login.use_popup = true;
jfbc.login.auto = '1';
jfbc.login.logged_in = false;
jfbc.token = '7738d73ba05753fd08d2f4a27640f728';
jfbc.init();
</script>
<meta name="twitter:card" content="summary"/>
<meta name="twitter:site" content=""/>
<meta name="twitter:title" content="Maheshwar (India: Madhya Pradesh)"/>
<meta property="og:title" content="Maheshwar (India: Madhya Pradesh)"/>
<meta name="twitter:image" content="www.travel-video.info/images/logos/logo-carre-1024.jpg"/>
<meta property="og:image" content="www.travel-video.info/images/logos/logo-carre-1024.jpg"/>
<meta property="og:type" content="article"/>
<meta property="og:url" content="www.travel-video.info/nl/videos/maheshwa...adhya-pradesh.html"/>
<meta property="og:description" content="Het kleine stadje in Madhya Pradesh met zijn Ahilya-fort aan de rivier de Narmada is een charmante plek."/>
<meta name="twitter:description" content="Het kleine stadje in Madhya Pradesh met zijn Ahilya-fort aan de rivier de Narmada is een charmante plek."/>
<meta property="fb:app_id" content="684332365457734"/>
<meta property="og:locale" content="nl_nl"/>
<meta property="og:site_name" content="Travel-Video.info"/>
<script type="text/javascript" src="//platform.linkedin.com/in.js?async=true"></script>
<script type="text/javascript">IN.init({
api_key: '86g8kytmhfkhw7',
authorize: false});</script>
<link rel="stylesheet" href="/media/sourcecoast/css/jfbconnect.css" type="text/css" />
<link href="www.travel-video.info/videos/maheshwar-madhya-pradesh.html" rel="alternate" hreflang="x-default" />

I also found out that my logo gives a "bad karma" page after I sent the message.
I found the URL by asking "Quantum Manager" to give me the URL of this image. Why we cannot see it with the URL is a kind of mystery to me.

The only SEF extension I use is sh404SEF and I experienced already lots of conflicts with other extensions like Route66 for instance.
As sh404SEF renames my URLs for pages the way I want it to do, I disabled all other extensions of the same kind. I have looked into the settings and could not find anything which could interfere in image URL's. But maybe I overlooked something.
I imagine this kind of problems is not caused by some instruction in .htaccess .
I also imagine I'm not the only one using sh404SEF. Providing the problem comes from that extension.