debugging on the server

I am using phpStorm and have developed my entire app with it.  I have uploaded the code to AWS. I can get it to start up fine by typing in the ipaddressofserver/sub_crud. However when I try to login to my app I get:

A PHP Error was encountered
Severity: Notice
Message: Undefined property: Users::$user
Filename: controllers/Users.php
Line Number: 84
Backtrace:
File: /opt/bitnami/apache2/htdocs/sub_crud/application/controllers/Users.php
Line: 84
Function: _error_handler
File: /opt/bitnami/apache2/htdocs/sub_crud/index.php
Line: 316
Function: require_once

This makes no sense to me since there is no mention of $user anywhere in that module! The code on line 84 is:
$checkLogin = $this->user->getRows($con);

Regardless, I think that for me to move ahead I will need to debug the code on the remote server, just so I can see what is going on. So I am trying to set up remote debugging. I have phpStorm on my PC and Putty with an ssh tunnel. I set the xdebug port in phpStorm to 8888 since that is the port for the tunnel (that Bitnami suggests). I am not getting any connection back to my debugger when I start up my app. 

Anyone have any idea what I am doing wrong? 

proof that an old dog can learn new tricks