Revealing mistake: The wires holding up Jacob Marley's floating lock box and chains are visible. (00:32:10)
Revealing mistake: The wires holding up Scrooge, as he is lifted to see the ghost of Christmas present, are visible.
Continuity mistake: When Cratchett gets the bird from the shop, it's clear that the bird is a duck. But throughout the entire film he's referred to as a goose.
Continuity mistake: When Isabel is breaking off the engagement with Scrooge (in Christmas past), the eye color of Scrooge changes to brown and then back to blue.
Factual error: When Scrooge is in the carriage with his girlfriend in the back, on the hill you can see a white van go past.
Suggested correction: I have replayed that scene over and over and I couldn't see a white van pass by.
Factual error: At the early stages of the movie, Scrooge is talking to a man who owes him money. Scrooge mentions the August Bank Holiday. Bank holidays were not introduced until 1871, after the period in which A Christmas Carol/Scrooge is set - around 1835 (Charles Dickens, the author of the book, died in 1870).
Suggested correction: Isn't this error in the 1950s Alistair Sim version?