Kaltura_Client_Exception thrown

Invalid KS "YzJlOGNkMDk1ZTU0ODhmZTg4ZTdlNWI5M2I1MzI4M2VjNzI5YjQ3OHwxMDE7OzE0OTA2NDk5NjI7MjsxNDkwNTYzNTYyLjU4NjE7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"