Kaltura_Client_Exception thrown

Invalid KS "MWRhNmExMTMzMGUyNmMzNTAxNWFkZTM4MjI3ODJhMTBlMmNhYjhiMXwxMDE7OzE0NzUyOTIzODQ7MjsxNDc1MjA1OTg0LjgzMDI7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"