Kaltura_Client_Exception thrown

Invalid KS "YzY1ZGIyOTYxZTJhOWJjYzBjOGM0YTdkYWFjMmYwMDNiMTVjMWNhZHwxMDE7OzE0NzU0Mjk1NzU7MjsxNDc1MzQzMTc1LjkxNTk7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"