title: Codeigniter 3 Session not working With PHP 7.1.4
body: <p>I have an application built with <code>Codeigniter 3 HMVC</code>.The application was working fine on PHP <code>5.6</code> version, But after upgrading my PHP version to <code>7.1.4</code> I was not able to log in into my application. After a complete checkup I found that session is not setting at all.</p>
  
  <p>I role back to PHP <code>5.6</code> and session was working fine again while switching to PHP <code>7.1.4</code>  bring the "session not working" issue back.</p>
  
  <p>I tried altering some config value like cookie prefix and cookie save name etc, nothing seems to fix it.</p>
  
  <p>Can anyone please help. </p>