He studied philology at the University of Vienna and received his doctorate in this subject. Klaren worked as a journalist and writer, wrote novels, essays and libretti. In 1922 he came to Vita-Film in Vienna as a dramaturge . From 1925 he worked mainly in Berlin and wrote film scenarios, often together with Herbert Juttke . Klaren was among other things co-author of Richard Oswalds Feme (1927), and Wilhelm Dieterle's sex in fetters (1928). In 1931 he wrote the German version of Mary of Alfred Hitchcock's murder - Sir John intervenes! With. That same year, Klaren made his directorial debut with the film Children in Court . After 1933 he worked as a screenwriter in both Germany and Austria. For a short time he became chief dramaturge at DEFA and had international success as a director and author with the film adaptation of Wozzeck (1947) based on the fragment by Georg Büchner . In the 1950s he lived and worked in Vienna again.
In an interview with the Berliner Zeitung in 1947, he stated that he had written more than 180 scripts.
Filmography
1926: Nanette does everything (screenplay)
1926: The Little One and the Cavalier (screenplay)
