Hi there. I tried now the things that you suggested.
1 – Only saving the post without change anything didn′t affect anything. The error persist.
2 – Changing the plugin setting on-view to ‘everytime your site is visited’ didn′t affect the Facebook Debug result BUT changed the result when trying to make a new post direct thru Facebook.
Now with the new option, if I grap the post link and try to post on Facebook, it gives me the chance to select 8 thumbnails instead of only one without the option.
BUT, none of this thumbs are related to the video of Youtube. Most are gifs and jpegs from social networks I have in my site.
3 – I don′t have any idea if my server settings is preventing this from work.
4 – I tried to use the Fedmich plugin but it also didn′t work.
:'(
Regards.