I have an application that has CodeIgniter version 3.1.0 and I am trying to "upgrade" to 3.1.2 (latest version)
I have no custom files in the System folder. I had renamed the system folder (for security reasons) and that change is in my index.php
As soon as I switch on the old system folder, application works just fine.
The error that I get is:
PHP Parse error: syntax error, unexpected T_CONST in C:\\prj\\www\\nbo\\systemXXYYZZ\\core\\CodeIgniter.php on line 58
LINE 37:defined('BASEPATH') OR exit('No direct script access allowed');
/* COMMENTS IN BETWEEN */
LINE 58: const CI_VERSION = '3.1.2';
const won't work on php version 5.2.x.
The latest version of codeigniter is supported only on php 5.3.7+, so I highly advice you to upgrade your PHP version.
You could downgrade your project to codeigniter 3.0.5, which is the last version that supports php 5.2.x, but it's not recommended.