disallowed key characters in codeigniter

I have faced ‘disallowed key characters’ error in codeigntier. Finally i have got solution of disallowed key characters’ error problem in codeigntier. Follow the elow step to resolved it :-



1. Goto system->core->input.php
2. Find the exit(‘Disallowed Key Characters.’);
3. Replace to exit('Disallowed Key Characters.' .  $str);
4. Also replace if condition if ( ! preg_match("/^[a-z0-9:_\/-]+$|/i", $str))
5. Refresh your web page.