Error message: What does it mean???

After making a few minor tweaks to my WP Config page, including changing the debug value from false to true, I got this message:

Deprecated: Assigning the return value of new by reference is deprecated in /home/content/03/12122203/html/InFocus/wp-content/plugins/add-new-users/add-new-users.php on line 480
Notice: wp_enqueue_script was called incorrectly. Scripts and styles should not be registered or enqueued until the wp_enqueue_scripts, admin_enqueue_scripts, or login_enqueue_scripts hooks. Please see Debugging in WordPress for more information. (This message was added in version 3.3.) in /home/content/03/12122203/html/InFocus/wp-includes/functions.php on line 3049

Can anyone advise as to what it means and how to resolve it?