Continuity mistake: When Tommy Tong breaks Jarrel's stick, the broken part of the stick differs between shots. (00:33:40)
Continuity mistake: After Chloe runs off into the woods and the other two girls finally find her after she's had her run in with Slender Man, they are shining the flashlight in her eyes and asking her questions. In one shot her eyes are still open as she gazes near blankly off in the distance. When it cuts to a close up and suddenly her eyes are tightly squinted shut. (00:38:45)
Continuity mistake: When Sgt. Howie inspects the register at the school the first shot of the Beltane Term page shows Rowan Morrison's address as 'The Tuck Shop', when it switches to a closer panning shot her address is changed to 'The Post Office'. (00:32:50)
Continuity mistake: During the first meeting between Lou and Madeline Kahn, her fur stole changes position between shots almost more often than she changes names. (00:09:30 - 00:10:30)
Visible crew/equipment: When the Jeep is flipping, in one shot, the door flies open and reveals that Ace is wearing jeans. Ace doesn't wear jeans throughout the whole movie showing that this is a stunt double. When the car falls in the parking spot, Greenwall seen through the door is very obviously a dummy.
Continuity mistake: In the gas station scene after Ellen learns that Phil has drowned, she is so distraught she forgets to put the gas cap on and we can see it on the roof of her car as she drives away. But when she arrives at the police station we can see that the gas cap is on. (01:10:20)