Complex sentence: The film was originally to be scored by Erich Wolfgang Korngold, however, production of the film was postponed until 1947, by which time Korngold had retired from scoring motion pictures.
Split into simpler sentences: The film was originally to be scored by Erich Wolfgang Korngold. However, production of the film was postponed until 1947, by which time Korngold had retired from scoring motion pictures.