Kaltura_Client_Exception thrown

Invalid KS "NmQ1OGNkMDg4MDU2NDdkZTZkNjc5Yzk0ZmQ3Y2IzOGQzMTk4MDljOHwxMDE7OzE0NzU0MjM5NzA7MjsxNDc1MzM3NTcwLjgxMjQ7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"