you have a number of different upload behaviors on this page and they are all set incorrectly.
In the upload folder, click the lightning bolt, and select the username session variable, this will add the following code:
<?php echo $_SESSION['username']; ?>
assuming the session is named username, it may look slightly different if your session uses a different name.
preface the auther/auther_files directory in front of that:
author/author_files/<?php echo $_SESSION['username']; ?>
NOTE: on pages that use a session, you may need to add the following code at line 1:
<?php @session_start(); ?>