I upgraded PHP the other day from v5.3 to v5.4.3 and my WP site would no longer load (blank/white screen).
The php error log had this to say:
PHP Fatal error: Call-time pass-by-reference has been removed; If you would like to pass argument by reference, modify the declaration of do_action(). in /[...]/wp/wp-content/plugins/file-gallery/includes/attachments.php on line 710
Whenever you need to pass an argument by reference, just wrap it in an array, like so:
do_action('file_gallery_delete_all_attachment_copies', $attachment_id, array(&$copies));
And fix for same error on line 761 of same file:
do_action('file_gallery_promote_first_attachment_copy', $attachment_id, array(&$promoted_id));
Using File-Gallery v18.104.22.168