Kaltura_Client_Exception thrown

Invalid KS "MzI0ZDhlN2EyODJlZDZmNmJlMjQ2ZDZhZjFjOThjNTI0MzVlZGM4YXwxMDE7OzE0OTU2NjU4MTY7MjsxNDk1NTc5NDE2LjU1NzU7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"