Kaltura_Client_Exception thrown

Invalid KS "YmIzZGExZDI3YTFiYTkzOTYxOWYwNGJlNzM5NDU1YTJiYmZiMmI1M3wxMDE7OzE0OTM1NzUyMjI7MjsxNDkzNDg4ODIyLjA1NjU7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"