Kaltura_Client_Exception thrown

Invalid KS "YWFhZjI0YWZhZTFkNzlhMmNkYzc1ZTBlYjI2NjFhZDQxMjViMzM2YnwxMDE7OzE0OTM2NzkxMTk7MjsxNDkzNTkyNzE5LjkxODk7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"