Best romance movie mistakes of 2016
Factual error: During the 31st year of the Avalon's voyage, the ship passes close to the star Arcturus, which is about 37 light years from Earth. Later in the movie, it was stated that the Avalon was moving at around 50% of the speed of light. The ship would not have reached Arcturus in the time allotted.
Continuity mistake: When Lady Susan is counseling her daughter Frederica in her bedroom, the shot shows an unlit candle on a dresser behind Lady Susan. The shot changes back and forth between Frederica and Lady Susan. When the shot changes back to Lady Susan, the unlit candle is gone, though there is no one else in the room.