Kaltura_Client_Exception thrown

Invalid KS "MTNkYTMzYmI4MmIyNWI5Y2I2ZTRiNTg3NTk0MWIwZTdlMWI1YThhNHwxMDE7OzE0OTM2MTAwNTA7MjsxNDkzNTIzNjUwLjUzMzM7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"