Hunnia-Film

Operetta star Gitta Alpar plays a singer engaged for a performance at the Savoy Hotel, where she mistakes Baron von Wollheim for a waiter. But the baron is content to play the game for a while and changes his role with the real waiter. Of course the singer is quite happy when she discovers the real identity of the baron, but now she mistakes him for a thief, as her necklet has gone missing. Further complications arise when the baron's cousin Mary, a composer, arrives at the hotel and wants a music publisher to listen to her songs.

A German-language film loosely based on the 1883 operetta Eine Nacht in Venedig (A Night in Venice) by Johann Strauss II. The film was also made into separate Hungarian-language version Egy éj Velencében based on the same screenplay. The two versions were shot simultaneously. The Hungarian version was co-directed by Wiene and Géza von Cziffra and used a separate cast of Hungarian actors. From Wikipedia.

The archduke's grandfather wants to thwart the love between Princess Erzsébet and András Balogh, a young man of lower rank. He sends Erzsébet to Switzerland and András Balogh to Warsaw as an embassy secretary. However, Erzsébet follows András to Warsaw, where they both become embroiled in criminal complications when András has to return home with important diplomatic documents. Back home, it turns out that everything happened so that Erzsébet could soften the archduke's grandfather's heart and rescue András from the predicament he got himself into for Erzsébet's sake... The film is set in Warsaw, and the exterior shots were taken just before the outbreak of World War II, so the film still shows Warsaw intact.