This is usually due to either a security plugin or a setting on your web server that is blocking the plugin from accessing the files needed to load the comments into the feed and the thumbnails into the lightbox. You can verify this by checking your web browser “JavaScript Console” to see whether there are any 404 or 500 Internal Server Errors: Failed to load resource: the server responded with a status of 500 (Internal Server Error)
Solution
1) If you have any security plugins installed then check to see whether they are blocking any specific file types
2) If your site is on an Apache server then check the “.htaccess” file in your WordPress root directory to see whether it is blocking all file types, like so:
Order deny,allow
Deny from all
If so then you can add an exception to the file to allow the plugin to access the files it needs to load:
<Files ~ "query.php$|comments.php$|thumbs.php$">
Allow from all
</Files>
If you’re not sure how to do this then you can contact your web host support team and ask them for assistance.
3) Ask your web hosting support team to check whether there’s anything on the server that is blocking the following files:
wp-content/plugins/custom-facebook-feed-pro/query.php
wp-content/plugins/custom-facebook-feed-pro/comments.php
wp-content/plugins/custom-facebook-feed-pro/thumbs.php
