Kaltura_Client_Exception thrown

Invalid KS "M2E0YzQ2M2QyMTNhMDQzNjUyOWJjZmRhYmI3ZDU1MGMyZjI2OTU1ZHwxMDE7OzE0OTg3OTYyNTE7MjsxNDk4NzA5ODUxLjU1NTY7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"