When announcing her trip to Mallorca George Sand mentioned to Chopin, that she surely won't be alone there, referring that Chopin will accompany her. However in real life she was moving to Mallorca with her kids Maurice and Solange. Chopin joined her some time later.
Frederic Chopin and George Sand first met in 1838 after they were introduced to each other by Franz Liszt. In the movie they met in a restaurant in 1832.
George Sand mentioned that Franz Liszt just returned from London. This happened in 1837 while the scene is set in 1832.
While Chopin's teacher Jozef Elsner was in Paris in the 19th century, he didn't joined Chopin to his trip to Paris in the 1830s. Chopin was taught in Paris by his idol Friedrich Kalkbrenner instead.
In 1831 Konstancja Gladkowska, Chopin's female friend, became 21, not 18, as said by Grabowsky in the movie.
The Polish Upraising that is portrayed in the movie started in November 1830, which is why it was called "November Upraising". In the movie the events take place in June 1831.
During the dance performance in Warsaw in 1831 Chopin's "Waltz Nr 7 in C-sharp minor Op. 64" is played, which however was written in in 1847.
Franz Liszt is shown playing Chopins Polonaise op. 53 in 1832 while it was written in 1842.