Kaltura_Client_Exception thrown

Invalid KS "NzZkZDBhY2UzMDAzOTJiNDBjZGY1MzczMTU1OWNhZmVlZGYyZWVlYnwxMDE7OzE0NzUzMDYyODM7MjsxNDc1MjE5ODgzLjQ4NjM7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"