Kaltura_Client_Exception thrown

Invalid KS "NzZkM2JhMTI0MzM5Nzk0ZjVmMTFkN2IxMDM4ODBhOWI1NTczN2JlYXwxMDE7OzE0Njk0NTg4ODQ7MjsxNDY5MzcyNDg0LjI2NDY7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"