(at around 57 mins) In one of the scenes the downstairs TV is seen falling over. Just afterwards the TV is straight back up without a scratch on it.
(at around 10 mins) The daughter said there were no malls yet just a few scenes later (at around 24 mins) the father sees the mall in his rear view mirror and goes on a shopping spree.
(at around 40 mins) During the sequence in which Madison is taken, the older daughter is trapped in the basement, yet comes running out of the front door screaming that her brother was grabbed by the tree. She would not have seen this happen and would have no knowledge of it.
(at around 47 mins) When Eric Bowen is drinking alcohol by the sink, the bottle moves to the left a few inches between scene changes.
(at around 10 mins) Before going to bed Griffin asks his mom to leave the "night-light" on, which she does. In the next scene with the kid, the light is off and the room is all dark. When Griffin's dad comes to check him out, the light is on again.
(at around 1h 6 mins) At one point in the film the family are asked to carry GPS trackers. These were supplied so as to track the family no matter were they are. Since the film takes place inside a family home the GPS trackers would be useless since they need direct or "line of sight to the sky" to "see" satellites in order to accurately track via GPS.
Griffins Drone, the "AR Drone 3" does not exist. The drone itself is a modified Bebop drone. Parrot (the company behind the drone) created the AR Drone 2.0, their next model was the Bebop.
During the climax of the film, Kendra pulls the TV off it's shelf, and it falls down with the screen facing up and she starts stamping on it. However, the TV is seen moments beforehand with its screen facing towards Kendra and the rest of the family. This means that if Kendra pulled the TV off, it should have fallen with the screen facing downwards.
However, if you watch closely, you'll see her rotate the TV so that the back is facing her just before she pulls it off of the stand.
(at around 1h 20 mins) When the family's car is pulled back into the house, Eric asks if everyone is okay but his mouth is not moving while he is stuck in the car.
(at around 1h 20 mins) When the car gets pulled over onto its side, the wire can be seen attached to the bonnet.
Nobody sees Madison after Griffin leaves her in the corner of her room. How do her parents know she disappeared through the bedroom closet as they describe to the investigators?
(at around 1h 15 mins) In one scene Carrigan Burke and Eric Bowen are in the upstairs room with the portal and Carrigan is shouting to the spirits. The scene then cuts to the others downstairs then back upstairs and the two men are incapacitated on the ground.