Kaltura_Client_Exception thrown

Invalid KS "NmFlMzUwZjE2NTgzYWQyMTZkNjQxNmIzZWFmMGZjODgxNzRkNjRmZHwxMDE7OzE1MDA4MDg1NTQ7MjsxNTAwNzIyMTU0LjAzMjk7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"