Goofs

In the opening shot a poster announces the premier of "The Tragedy of St. Joan" as Monday, November 27, 1900. November 27, 1900 fell on a Tuesday.

All the times we see the Phantom prior to being unmasked, his forehead above the mask is clean. But for a split second before he rips the mask off, a small scar is visible on the right side of his forehead.

Even tho the story takes place in the late 1800's/early 1900's a modern exit sign is present in the shot of the haunted box.

The film, set in the Edwardian period (around 1900), features an opera called "Saint Joan". But Joan of Arc was not canonized until 1920.

A boom crane is visible in Christine's dressing room mirror briefly when the Phantom first speaks to her.

During the hanging of the stagehand during the opening scene, the wires holding the actor are visible on either side of the rope.

During the flashback sequence, Ambrose D'Arcy writes his own name on the title page of one of Professor Petrie's manuscripts, which is called Symphony No. 1. The word 'symphony,' however, is incorrectly spelled 'symphany.' The spelling is corrected on the printed copies of the music seen later.