Vimeo RSS feed shortcode doesn’t display in custom post type

I have a problem with the shortcode of a slider wordpress plugin called Justified image grid and working with vimeo RSS feeds. If I add a shortcode in a normal wordpress page, it works very well but if I add a shortcode on a meta box created in a custom post type, it shows an error with XML.

I get this error : “The requested RSS feed cannot be loaded at this time. This XML document is invalid, likely due to invalid characters. XML error: XML_ERR_NAME_REQUIRED at line 1, column 2”

I don’t understand, my rss feeds are well validate. I tasted it several times.

here is the RSS url :

I tried to convert it with feedburner by google but I got the same bug… I tried also to add ?format=xml but nothing changes…

Here is the php code to call the RSS feed :

<div class='vimeo-rss-container'>             <?php echo do_shortcode('[justified_image_grid preset=17 caption_field=off row_height=300 height_deviation=70 prettyphoto_theme=dark_rounded lightbox=magnific lightbox_max_size=full last_row=match disable_cropping=yes link_target=video rss_url=' . get_post_meta($  post->ID, '_director-vimeo', true) . '/rss rss_links_to=permalink rss_description=description rss_link=yes rss_link_text="Watch on Vimeo"]'); ?>           </div> 

Something wrongs in the PHP? Anybody could help me?

I really appreciate! Thanks a lot! Martin