Kaltura_Client_Exception thrown

Invalid KS "YzM5MzAxNGI5NDAxMWE0NDRlMDBkMzA1NDNiNjhlOGJjOGViMDMyMnwxMDE7OzE0NzU0MzAxNTY7MjsxNDc1MzQzNzU2LjUyMzY7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"