During the climactic ballet, the spelling on the tombstone alternates between COLUMBINE and COLOMBINE.
During the final comedy act, the pianist's chair changes between shots.
When Calvero returns after his failure to revive his career at the Middlesex Music Hall, the clock on the mantelpiece behind Thereza jumps back and forth 45 minutes.
When Calvero returns to his boarding house with a bag of fruit, it is light outside as he climbs the steps to the front door, but the interior shot of him coming through the door shows darkness outside.
While Thereza is convalescing in Calvero's apartment, Calvero is shown removing a soiled towel and placing it in a large bowl on the bed. In the subsequent wider shot, the bowl is no longer there.
The film begins in the summer of 1914, as the First World War began, but less than a year passes before a newsboy shows a headline "United States Enters War", which didn't happen until April 1917, and Neville is drafted, though the draft did not begin until 1916. Curiously, only one person appears in uniform, despite England being on a war footing.
The letter Calvero receives from Redfern states that his performance at Middlesex is on Monday 5 September. In 1914, when the scene is supposed to take place, 5 September was a Saturday.
In discussing the ballet with the cast, the dance director Bodalink casts a giant shadow in front of the auditorium seats (revealing it to be nothing more than a backdrop).
The movie is set in 1914, but the opening street scene shows people dressed in clothing from a much later time period, particularly the women. Correct women's clothing is not apparent until the landlady appears.