Continuity mistake: When Nica gets in the elevator to take Chucky up to Alice, when she closes the door, her right arm is suddenly fully extended to flip the switch between cuts.
Continuity mistake: When the nanny notices that the knife is missing, right before Barb starts kissing her, the knives on the rack change when it cuts back to a closeup. Noticeably, the butcher knife from the first shot has been replaced with a much smaller standard carving knife. One of the other knives has also rotated about 20 degrees.
Continuity mistake: When the babysitter is helping the little girl find Chucky, at one point, she puts a piece of luggage on the bed and opens it up. The paper luggage tag on the bag confusingly keeps moving back and forth between the handle of the bag and the zipper, depending on the shot.
Continuity mistake: When the family is watching old home movies and Barb complains, "It's called 'baby-fat'!", Nica's mouth goes from closed to open between cuts, and her hand goes from being on her face to off between the same cut.
Continuity mistake: When the officer tries to talk to Father Frank at the crash site, he goes from standing to leaning forward towards Frank between cuts.
Continuity mistake: If you look closely during the dinner scene, during the first overhead shot when the camera is rotating above the table, you can just barely tell that all the candles were burned down. They are taller through the rest of the scene. That shot was filmed last, by which point all the candles had considerably shrunk. (Confirmed in Blu-Ray commentary.)
Continuity mistake: When Nica gets into an argument with Barb about selling the house, when Nica tosses the pamphlet on the table, the way she's holding it changes instantly between cuts.
Continuity mistake: When Barb shows Nica the pamphlet for the assisted living centre, after Nica says "What is this?", the way Barb is holding her hands on her knees changes instantly between cuts. The teacup in front of Barb also rotates slightly between cuts.
Continuity mistake: Sarah's mouth goes from open to closed to open again between cuts after she takes Chucky out of the box, and Chucky says, "Hi, I'm Chucky! Wanna play?"
Continuity mistake: When Sarah pulls Chucky out of the box, the amount of packing peanuts stuck to Chucky's head/hair changes between cuts.
Continuity mistake: When Nica's mother shuts the door after the package arrives, she rotates about 45 degrees towards Nica between cuts.
Continuity mistake: When the delivery man hands Nica the gizmo, the sign for the package, it rotates 180 degrees between shots. (You can really tell from the direction the antenna is pointing.)
Continuity mistake: When Nica opens the door for the delivery man, she's still opening it, but then the shot cuts and she's no longer opening it and is instead rolling forward towards the driver in her wheelchair.
Continuity mistake: In the previous films, the Good Guy dolls always say "Hidey-Ho!" before their trademark "Ha-ha-ha!". For some reason, this movie omits that.
Continuity mistake: When Nica is woken up by the screams she's wearing a sleeveless night gown. When she peers into her mother's room she's wearing a long sleeve shirt, but when she exits the elevator a few seconds later she's wearing the sleeveless gown again.
Continuity mistake: When Chucky pushes Nica over the balcony, the camera shows her falling to the floor on her back but when the camera zooms out on her, it shows her lying on her stomach.
Suggested correction: You don't see her land, and she's off-screen for a solid 15 seconds. It's entirely possible she hit the ground and rolled onto her stomach.