Kaltura_Client_Exception thrown

Invalid KS "YzNhNGJkYzBlMDY5Nzg0MWY0N2I4MjZjMzg3MmFjYjVhNWNjNWJmMXwxMDE7OzE0OTM1NTA3ODI7MjsxNDkzNDY0MzgyLjUxMDQ7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"