Kaltura_Client_Exception thrown

Invalid KS "MDljYzI5NGQzOWViMmM0YzUxYjkwZWY2ZTQ5ZjExNzhiZGM4MzczZHwxMDE7OzE0NzI3ODI1OTg7MjsxNDcyNjk2MTk4LjgwMjQ7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"