Kaltura_Client_Exception thrown

Invalid KS "MWI4YzFmZjljYTNhMmY2ODUyN2Q2OGU5M2RiMmI4MDhlZTFkMWU0MnwxMDE7OzE0OTMzODUxODg7MjsxNDkzMjk4Nzg4LjE2OTc7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"