title: session error in codeigniter?
body: <p>when I want to set session data in codeigniter 3 it says error like:</p>
  
  <pre><code>A PHP Error was encountered
  
  Severity: Warning
  
  Message: mkdir(): Invalid path
  
  Filename: drivers/Session_files_driver.php
  
  Line Number: 117
  
  Backtrace:
  
  File: C:\xampp\htdocs\ci-test\application\controllers\login.php
  Line: 7
  Function: __construct
  
  File: C:\xampp\htdocs\ci-test\index.php
  Line: 292
  Function: require_once
  </code></pre>
  
  <p>Here is the code that where want to set session data.</p>
  
  <pre><code>$sess_array = array(
           'id' =&gt; 1,
           'username' =&gt; 'bikramkc.kc@gmail.com'
         );
  $this-&gt;session-&gt;set_userdata($sess_array);
  </code></pre>