Revealing mistake: The stepmother's arm disappears for a split second when she tells her daughters that there is still a chance for them to become the princess.
Other mistake: When the clock strikes 8 o clock, the 11 (XI) on the clock reads 12 (XII) in roman numerals. This is just in-between the scene with the mice making Cinderella's ball dress and the scene where the carriage arrives at the home to pick the stepmother and stepsisters up for the ball. (00:36:50)
Audio problem: After Cinderella has run away from the Prince and everything goes back to normal, she discovers that the Fairy Godmother has left her with a single glass shoe. She then proceeds to thank the Fairy Godmother.she says "Thank you so much.for everything." When she says "for", her mouth doesn't move correctly.her mouth is supposed to close in order to say the beginning "f" part, but it remains open, so it looks like she's actually saying "hor" instead of "for".
Other mistake: At the beginning of the movie, where Cindy opens the drapes outside of her stepsisters' bedrooms, you can see a slight stutter in her walk just as she reaches for the drapes. Looks like a camera mistake - the cels were out of sequence there.
Deliberate mistake: In the famous sequence where the pumpkin turns into a carriage, the fairy godmother stands behind it waving her wand and doing the magic. First mistake: After the transformation, the fairy godmother is stuck in freeze frame with her hands up in the air for the entire time when Cinderella is saying how lovely the carriage is. Another mistake occurs when it cuts to the fairy godmother (after the freeze frame), because her arms are suddenly down and she is moving and talking to Cinderella.
Continuity mistake: When Cinderella opens the curtain before waking up Lucifer, the hallway has a large window, a mirror and a stool beside the the stairs, but a door to music room has appeared on the hallway when Lucifer escapes the singing and playing of the stepsisters. This can be also noticed when stepmother hears Cinderella humming the ball waltz and goes after her, the window is back in its place rather than the door. The carpet is also covering whole floor in the scene where Lucifer exits the non-existing music room and the railing is shorter than in other scenes. (00:09:50 - 00:26:25)
Continuity mistake: When Cinderella ascends the stairs with three breakfast trays, Gus is under the cup in her right hand tray. That right hand tray (with Gus) is dropped off in the first of the three rooms in order, which is Drizella's room. When screams are eventually heard and Lucifer runs to catch Gus, they come from the second (middle) door, which is Anastasia's room and it's Anastasia who had the mouse.