Factual error: The credits list several of the characters as "Arab." But the film is set in Afghanistan and the Afghans are not Arabs.
Plot hole: Every ghost that we see in the house looks the way they did when they died, for example the girl from the film's intro is seen without skin on her face, which happened to her before she died. However, in the final scene when we see Simon's ghost joining them, he looks completely normal, when he should have had a throat slit wound and the carved markings on his skin. (01:31:20)
Revealing mistake: In the evil woman's dramatic scene after she kills the children, her knife flops around like it is made of rubber, but sounds solid when she throws it in the sink. (01:22:35)
Visible crew/equipment: As the camera circles Nelson exiting the SUV, you can see crew members in the RS mirror as he shuts the door. (00:26:40)
Continuity mistake: When she gets the pizza from the guy at the door, it is in a white box. When she goes in and sets it on the counter, it is in a brown pizza box. Then later, when she is running away covered in blood, she grabs the knife on top of the pizza box, and it is white again.
Continuity mistake: When Frida is in her room and throws the stuffed animal near the window, she sees a zombie in the pouring rain across the street. However when her boyfriend startles her in the window, he is dry and the rain and wind instantly stopped.
Continuity mistake: When she hits him in the privates, making him faint, his head is first turned to the right, but then it's turned to the left for the rest of the scene. (01:12:15)
Continuity mistake: During the sex scene between Alex Pettyfer and April Pearson, April Pearson is not wearing a shirt. However, as Alex Pettyfer is dragged out of the car, she is suddenly wearing her shirt again.
Continuity mistake: When Lotte is tied down to the altar and is talking to Jimmy, the cut on her face alters constantly from the left cheek and right cheek throughout the conversation.