Facebook pubblicize problem

When you share a post on Facebook, or when Jetpack Publicize publishes a post to your Facebook page, Facebook crawls the page and looks for Open Graph meta tags in the head to build a complete post preview (with an image, title, description, …).

Jetpack automatically creates these Open Graph Meta tags for you unless you already use another Open Graph plugin, in which case we let the other plugin handle things.

You can see what Facebook sees by entering one of your posts’ URLs in Facebook Debugger:
https://developers.facebook.com/tools/debug

Whenever Facebook runs into errors when trying to crawl the post, it will reject the Publicized post. That seems to be the problem on your site at the moment. Here is the message we received from Facebook when we tried to publicize one of your latest posts:

Error 500 (Invalid parameter) -- More Than One OG URL Specified: Object at URL 'http://www.lecodellitorale.it/2015/07/17/la-strada-verso-olympia/' of type 'article' is invalid because it specifies multiple 'og:url' values: http://www.lecodellitorale.it/2015/07/17/la-strada-verso-olympia/, http://www.lecodellitorale.it/2015/07/17/la-strada-verso-olympia/. [1611070]

Looking at that post, I see 3 different sets of tags:

1. One is added by the WordPress SEO plugin.
2. The other is added by Jetpack.
3. The third one is most likely added by your theme.

To get rid of that error and solve the issue, you’ll consequently need to get rid of 2 sets of tags. I’d suggest the following:

1. Deactivate the “Always Use Jetpack Open Graph Meta Tags” plugin you installed on your site.
2. Check your theme options and deactivate your theme’s Open Graph Meta tags. If your theme doesn’t include an option to do so, get in touch with the theme authors and ask them how to remove the tags from your theme.

Once you get rid of the duplicate sets of tags, you should be all set!