Session doesn't work after update from 2.2.1 to 3

Have you read and followed:
https://www.codeigniter.com/userguide3/i...e_300.html

Have you tried:
http://lmgtfy.com/?q=%22Unable+to+locate...ion.php%22

Yes, Sir this is how the config.php looks now 
$config['sess_cookie_name'] = 'ci_sessions';
$config['sess_expiration'] = 86400; //24 hours
//$config['sess_expire_on_close'] = TRUE;
//$config['sess_encrypt_cookie'] = FALSE;
$config['sess_use_database'] = FALSE;
$config['sess_table_name'] = FALSE;
$config['sess_match_ip'] = FALSE;
//$config['sess_match_useragent'] = TRUE;
$config['sess_time_to_update'] = 86400; //24 hours
$config['sess_driver'] = 'database';
$config['sess_save_path'] = 'ci_sessions';

Still I am getting the same error.