Kaltura_Client_Exception thrown

Invalid KS "YTYzOWRjYzNkY2U4YTFhMjdhZWQ5YmJmOGFmZTUyYWMzMTg1M2I5ZnwxMDE7OzE0OTMyNjc4NTU7MjsxNDkzMTgxNDU1LjI2NzI7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"