Kaltura_Client_Exception thrown

Invalid KS "MTJkOTUyYWNlMGU3OGJmYWE0ZDZhZTg5ZmIzM2VlZWQyYjg1YTc3NHwxMDE7OzE0OTU5MTI5NjE7MjsxNDk1ODI2NTYxLjM3MjM7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"