Kaltura_Client_Exception thrown

Invalid KS "YzFkNmUwZmEzN2M3NGJkMGIyOGNiYjZhZTM2MDU3NmNjYmUxOTVkY3wxMDE7OzE1MDA3Mjg5NDc7MjsxNTAwNjQyNTQ3Ljg0NTM7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"