set_userdata doesn't realy set userdata

Your sessions table may need to be modified since the table schema for sessions changed in CI 3: http://www.codeigniter.com/userguide3/li...ase-driver

MySql example:

Code:

CREATE TABLE IF NOT EXISTS `ci_sessions` (
      `id` varchar(40) NOT NULL,
       `ip_address` varchar(45) NOT NULL,
       `timestamp` int(10) unsigned DEFAULT 0 NOT NULL,
       `data` blob DEFAULT '' NOT NULL,
       PRIMARY KEY (id),
       KEY `ci_sessions_timestamp` (`timestamp`)
);

Note that the `data` field is now a blob data type.