Hello Dear Stack Overflow friends! I've been trying to solve this problem for a couple of days with no success. I've read almost every post available here at Stack Overflow but I can't find out how to solve this.

When I share a link on Facebook, the thumbnail corresponds to the image I defined in the 

meta property="og:image" 

It works and everything is fine there... But,

I would like that each post could display its own featured image as a thumbnail when shared. How on earth can I do that? 

I've tried with this code in function.php

```
    function insert_image_src_rel_in_head() {
    global $post;
    if ( !is_singular()) //if it is not a post or a page
        return;
    if(!has_post_thumbnail( $post->ID )) { //the post does not have featured image, use a default image
        $default_image="http://example.com/image.jpg"; //replace this with a default image on your server or an image in your media library
        echo '<meta property="og:image" content="' . $default_image . '"/>';
    }
    else{
        $thumbnail_src = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'medium' );
        echo '<meta property="og:image" content="' . esc_attr( $thumbnail_src[0] ) . '"/>';
    }
    echo "
";
} add_action( 'wp_head', 'insert_image_src_rel_in_head', 5 );

```

And nothing happens...

I've also tried this code in header.php

```
    <?php
global $wp_query;
$thePostID = $wp_query->post->ID;
if( has_post_thumbnail( $thePostID )){
    $thumb_id = get_post_thumbnail_id( $thePostID );
    $image = wp_get_attachment_image_src( $thumb_id );
    echo '<meta property="og:image" content="'.$image[0].'" />';
} ?>

```

No success there either.

The featured image is activated in the functions.php like this.

```
add_theme_support('post-thumbnails');

```

As I said, all og tags are set.

What Is happening? It's not a cache thing because I'm using the facebook debugger to flush it.

I will be eternally grateful if anybody out there can help me.

Thanks a lot.

Benjamin.
['https://Stackoverflow.com/questions/15127388', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/2118014/']
I just found that code in my production.log

```
GET "/assets/&&!yt.test(e)&&(v.support.htmlSerialize||!wt.test(e))&&(v.support.leadingWhitespace||!pt.test(e))&&!Nt[(vt.exec(e)||["

```

Rails 3.2.13 dealt with it with `Completed 406 Not Acceptable`
I found the same in my logs but in november 2012:

`ActionController::RoutingError (No route matches [GET] "/assets/&&!yt.test(e)&&(v.support.htmlSerialize||!wt.test(e))&&(v.support.leadingWhitespace||!pt.test(e))&&!Nt[(vt.exec(e)||["):`