Operetta (German: Operette) is a 1940 musical film directed by Willi Forst and starring Forst, Maria Holst and Dora Komar.
 The film was made by Wien-Film, a Vienna-based company set up after Austria had been incorporated into Greater Germany following the 1938 Anschluss.
 It is the first film in director Willi Forst's "Viennese Trilogy" followed by "Vienna Blood" (1942) and "Viennese Girls" (1945).
 The film portrays the life of Franz Jauner (1832–1900), a leading musical figure in the city.
 It is both an operetta film and a Wiener Film.
Burgtheater is a 1936 Austrian drama film directed by Willi Forst.
 Most of the film was shot in the Burgtheater in Vienna.
William Nigh (October 12, 1881 – November 27, 1955) was an American film director, writer, and actor.
 His film work sometimes lists him as either "Will Nigh" or "William Nye".
Kaiserjäger is a 1956 Austrian film directed by Willi Forst.
Gently My Songs Entreat (German: Leise flehen meine Lieder ) is a 1933 Austrian-German musical film directed by Willi Forst and starring Marta Eggerth, Luise Ullrich and Hans Jaray.
 Art direction was by Julius von Borsody.
 The film is a biopic of the composer Franz Schubert (1797–1828).
 It was Forst's directorial debut.
 A British version was made called "Unfinished Symphony".
 The German title refers to the first line of the Lied "Ständchen" (Serenade) from Schubert's collection "Schwanengesang", "the most famous serenade in the world", which Eggerth performs in the film.
Viennese Girls (German:Wiener Mädeln) is a 1945 historical musical film directed by Willi Forst and starring Forst, Anton Edthofer and Judith Holzmeister.
 The film was made by Wien-Film, a Vienna-based company set up after Austria had been incorporated into Greater Germany following the 1938 Anschluss.
 It was the third film in Forst's "Viennese Trilogy" which also included "Operetta" (1940) and "Vienna Blood" (1942).
 The film was finished in 1945, during the closing days of the Second World War.
 This led to severe delays in its release, which eventually took place in 1949 in two separate versions.
 One was released by the Soviet-backed Sovexport in the Eastern Bloc and the other by Forst.
Willi Forst, born Wilhelm Anton Frohs (7 April 1903 – 11 August 1980) was an Austrian actor, screenwriter, film director, film producer and singer.
 As a debonair actor he was a darling of the German-speaking film audiences, as a director, one of the most significant makers of the Viennese period musical melodramas and comedies of the 1930s known as "Wiener Filme".
 From the mid-1930s he also recorded many records, largely of sentimental Viennese songs, for the Odeon Records label owned by Carl Lindström AG.
Miracles Still Happen (German: Es geschehen noch Wunder) is a 1951 West German romantic comedy film directed by Willi Forst and starring Forst, Hildegard Knef and Marianne Wischmann.
 It was intended by Forst as a more harmless follow-up to his controversial "Die Sünderin" which had also starred Knef.
The Prince of Arcadia (German: Der Prinz von Arkadien) is a 1932 Austrian-German romance film directed by Karl Hartl and starring Willi Forst, Liane Haid and Hedwig Bleibtreu.
 It premiered on 18 May 1932.
A Student's Song of Heidelberg (German:Ein Burschenlied aus Heidelberg) is a 1930 German musical film directed by Karl Hartl and starring Hans Brausewetter, Betty Bird and Willi Forst.
 It marked Hartl's directoral debut.
 The film is in the tradition of the nostalgic Old Heidelberg.

Question: Were Willi Forst and William Nigh both actors?
Answer: yes