Continuity mistake: When the truck crashes through the gate you can see there is nothing on the front bumper other than two fog lights. But when they start spraying blood there are nozzles attached to each end of the bumper. (00:01:10)
Continuity mistake: Near the very beginning of the movie, Arthur (Tony Shaloub) trips over his son's scooter and spills coffee on himself; throughout the scene, the stain keeps changing size and location. (00:13:10)
Revealing mistake: When the Lawyer plays the videoclip on the laptop, the stop button is pressed down all the time, instead of the play button. (00:14:40)
Other mistake: In the scene where Cyrus's Nephew first sees the kids in the in the machine. (1:18:45) The shot goes back and forth from him to the machine. The first 2 time the glasses are fine the last shot (1:18:550 The prescription inserts in the glasses are crooked. Bad editing. (00:18:45 - 01:18:55)
Continuity mistake: When Rafkin is dressed as the power guy, he goes into the basement, then collapses by a glass screen. Between shots the spells written on the glass screen behind him keep changing back and forth. (00:26:20)
Continuity mistake: When Rafkin enters the study where the Lawyer and Arthur are, he puts his toolbelt on the table. During following shots, it constantly changes position. (00:27:35)
Continuity mistake: When Kathy enters her bedroom she falls backwards onto her bed. In one shot her head is resting on an all-white pillow, yet in the next closeup her head is now resting on a white pillow with gold tassels attached to it. (00:29:20)
Other mistake: When Maggie puts the "magic" glasses for the first time, you can see that the light in the right (left to us) lens sparks and then turns off. In the next scene it works fine. (00:31:21)
Continuity mistake: When Kathy is sitting on the bathtub, washing her face in front of the Angry Princess, blood stains around the bathtub near the drain keep disappearing and reappearing. (00:36:15)
Continuity mistake: When Kathy is sitting on the bathtub, washing her face in front of the Angry Princess, how far rolled up her sleeves are changes, depending on the shot. (00:36:20)
Continuity mistake: When Arthur gets mad, he picks up a wooden chair and starts banging the glass. In one shot the actual seat part of the chair flies off, yet in the next frontal shot it is still attached. (00:38:50)
Continuity mistake: When Dennis points to the wiritng and says "these are containment spells," the actual handwriting he is pointing at is totally different between shots. (00:41:15)
Continuity mistake: When The Jackal throws Kathy up against the glass, we see Arthur drop Bobby's tape recorder in a frontal shot. Yet in a shot from behind as he begins to run, the tape recorded has now vanished. (00:48:50)
Factual error: When The Jackal attacks Kathy, it holds her up against the glass with one hand. It then begins to swipe her with both hands, but she still stays up against the glass. (00:48:55)
Continuity mistake: When Kathy is attacked by the Jackal, he claws at her right breast and it falls out of the bra. In the next shot her breast is back in the bra perfectly. (00:49:00)
Visible crew/equipment: During the scene in the library when Matthew Lillard is forced to tell the husband who the 13th ghost is, you can see the director's face through the glass wall in the bottom left while they are carrying out the glass panel. (01:01:15)
Continuity mistake: After Kalina whacks Maggie with the book, her glasses change from crooked to straight between shots. (01:10:05)
Continuity mistake: When we see Arthur counting the ghosts on his fingers, he has a silver ring on his left hand. However when the house is exploding, we see him huddled with Kathy and Bobby, and his left hand has no ring on. (01:16:35)
Continuity mistake: When Arthur hits Cyrus at the end, as Cyrus flies back you can see Bobby's scooter standing up, behind him. This has just suddenly appeared out of nowhere... (01:18:35)
Revealing mistake: When Arthur hits Cyrus at the end, Cyrus flies back and hits the floor. The floor is meant to be solid and sturdy, yet clealy wobbles when Cyrus hits. (01:18:35)
Suggested correction: Cyrus was an occultist, it is presumed that this video was haunted. That can also explain why he answers what they key is for in the video after someone asks what it's for.
This theory does not hold up because Cyrus is alive. He's just been wearing a prosthetic neck piece with a popped blood pack in it to appear as a ghost the whole time, in case he's seen walking the house during the plan.