A PHP Error was encountered

Severity: Notice

Message: Trying to access array offset on value of type null

Filename: common/admin_side_nav.php

Line Number: 12

Backtrace:

File: /var/www/html/rtm/application/views/common/admin_side_nav.php
Line: 12
Function: _error_handler

File: /var/www/html/rtm/application/helpers/custom_helper.php
Line: 7
Function: view

File: /var/www/html/rtm/application/views/layout_admin.php
Line: 22
Function: force_loadview

File: /var/www/html/rtm/application/controllers/Home.php
Line: 230
Function: view

File: /var/www/html/rtm/index.php
Line: 324
Function: require_once