Setting sess_save_path correctly

Hi, I've just uploaded my first ci app to my host provider's server after working on it in apache's localhost. The welcome controller worked fine, but when I tried to access my ion auth login, I got the following error...

Code:

A PHP Error was encountered

Severity: Warning

Message: mkdir(): Invalid path

Filename: drivers/Session_files_driver.php

Line Number: 117

Backtrace:

File: /home/leke/public_html/ci/application/core/MY_Controller.php
Line: 9
Function: library

File: /home/leke/public_html/ci/application/core/MY_Controller.php
Line: 52
Function: __construct

File: /home/leke/public_html/ci/application/controllers/admin/Dashboard.php
Line: 9
Function: __construct

File: /home/leke/public_html/ci/index.php
Line: 292
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: Cannot modify header information - headers already sent by (output started at /home/leke/public_html/ci/system/core/Exceptions.php:272)

Filename: core/Common.php

Line Number: 568

Backtrace:

An uncaught Exception was encountered

Type: Exception

Message: Session: Configured save path '' is not a directory, doesn't exist or cannot be created.

Filename: /home/leke/public_html/ci/system/libraries/Session/drivers/Session_files_driver.php

Line Number: 119

Backtrace:

File: /home/leke/public_html/ci/application/core/MY_Controller.php
Line: 9
Function: library

File: /home/leke/public_html/ci/application/core/MY_Controller.php
Line: 52
Function: __construct

File: /home/leke/public_html/ci/application/controllers/admin/Dashboard.php
Line: 9
Function: __construct

File: /home/leke/public_html/ci/index.php
Line: 292
Function: require_once

After a little googling, I found adding changing $config['sess_save_path'] from NULL to sys_get_temp_dir(); in config.php fixed the problem. Reading up on this led me to https://www.codeigniter.com/user_guide/l...sions.html and there it was suggested I load $this->load->library('session'); after parent::__construct() in MY_Controller. Trying this (after setting $config['sess_save_path'] back to NULL) gave me an error again, so I'm back to the sys_get_temp_dir(); as the value to $config['sess_save_path'].

So my question is, is this a usual thing when setting up the live app environment, or should I be concerned about something at this stage? As a noob, it's quite hard to ask questions about something I am new to, but I'm just trying to make sure I'm not going too far off track here while trying to understand as much as possible.

Thanks.