[eluser]truman_truman[/eluser]
Solved. The problem was that I had created the db table, copying and pasting from the codeigniter manual, which is translated into Spanish, surely has some error.
Now I copied from the official and working properly, thanks, greetings.
CREATE TABLE IF NOT EXISTS `ci_sessions` (
session_id varchar(40) DEFAULT '0' NOT NULL,
ip_address varchar(45) DEFAULT '0' NOT NULL,
user_agent varchar(120) NOT NULL,
last_activity int(10) unsigned DEFAULT 0 NOT NULL,
user_data text NOT NULL,
PRIMARY KEY (session_id),
KEY `last_activity_idx` (`last_activity`)
);
(Solucionado. El problema era que yo había creado la tabla de la db, copiando y pegando desde el manual de codeigniter, que está traducido al español, seguramente tiene algun error.
Ahora lo copié de la pagina oficial y funciona correctamente, gracias, saludos.)