Crew or equipment visible: After Arthur punches Rafkin and they fall to the floor you can see the refection of a crew member behind Arthur on the desk.
Crew or equipment visible: A crewmember with a clapperboard can be seen very fleetingly during the "bloody bathroom" scene.
Crew or equipment visible: A clapperboard can be seen when Bobby is being lured downstairs.
Revealing mistakes: The family is looking at the computer with the lawyer and he plays the movie. The stop button is pressed during the whole movie clip , where as the play button should have been pressed.
Revealing mistakes: When the jackal is attacking Arthur, his left hand disappears and reappears between shots.
Audio/visual unsynchronized: When Rafkin is explaining the Black Zodiac to Maggie, his mouth does not match the words that are being spoken.
Continuity: The position of the picture of The Hammer in the Arcanim.
Revealing mistakes: Jackal casts shadows on the walls before he attacks Arthur.
Continuity: When the Jackal attacks Kathy, he has one hand on her throat, which is what is holding her up, but when he lets go she does not fall down.
Revealing mistakes: As Arthur and Kalina discover that Kathy has disappeared, one of the walls moves when they lean on it.
Continuity: The stain on Arthur's shirt changes from shot to shot.
Continuity: After Kathy is attacked, the marks on her face disappear in the next shot.
Continuity: Just before everyone is looking through the book in the library, Rafkin has blood all over his right hand. But a little while later, his hand is completely clean.
Revealing mistakes: In the library when Dennis presses his bloody face to the glass, you can spot various other bloody face smears at his head height from previous takes.
Continuity: At breakfast the father has coffee spilled on him. When he opens the door to greet the lawyer the shirt stain is much larger, but then gets small again as they cut to the inside of the apartment.
Continuity: When the Angry Princess lies in the tub, Kathy's sleeves are alternately up/down between shots.
Continuity: When Kathy is attacked by the Jackal, he claws at her right breast and it falls out of the bra (but her nipple covered by a scrap of her shirt). In the next shot, her breast is back in the bra perfectly.
Crew or equipment visible: When the house starts to transform inside, a pair of hands of the crew can be seen pushing one of the doors when it is supposed to close automatically.
Continuity: During the glass house explosion, Arthur's wedding ring disappears.
Plot holes: It established that Arthur has no money. He has past due bills, he cannot afford a bigger house, and he is a math teacher. How does he afford a live-in nanny?
Plot holes: Dennis said that the walls of the house were soundproof, but when he is trapped in the room with one of the ghosts, Maggie is yelling at him to move and duck. He can clearly hear her, and she can hear him, even though he isn't supposed to be able to.
Continuity: Kalina tells Arthur that she slipped through an opening in the house, and that it was probably closed now. This is confirmed by the shot of the house being completely sealed with the metal plating. However, there are several shots in the basement where you can see a glass window with a tree branch/Bush outside.
Errors made by characters (possibly deliberate errors by the filmmakers): Dennis states that anyone who touches him, has their whole life flash before his eyes. Yet Maggie clearly touches him on the back several times while in the basement, and nothing happens to him, not even a twitch.
Audio/visual unsynchronized: Bobby falls on the floor in the basement, dropping his recorder. In the background, amongst the many whispers of the ghosts, Jean warns Bobby to get up and leave the basement. Right after that, a voice whispers in the background, and the caption reads "Leave me alone." However, with the volume turned up, the voice (belonging to the Jackal) clearly cackles a sarcastic 'Listen to your mother!'
Revealing mistakes: In the Arcanim, they mixed the Angry Princess's and the Bound Woman's pictures.