Plot hole: When the cop shows Pam the newspaper clippings they include what look to be fresh photos of the real Jason from the events of Part IV, yet no photographer is ever seen taking pictures of Jason alive in the previous films and most likely wouldn't live long enough to publish the photo. (01:25:00)
Suggested correction: The picture was taken from security footage at the hospital after killing the 2 employees.
It was never shown.
Revealing mistake: When Charley stabs Dandridge in the hand with his pencil, he stabs the hand holding him by the neck. The depth of the wound on Dandridge's hand reveals that the pencil should have stabbed Charlie in his neck and given him a severe wound, if not kill him.
Visible crew/equipment: In the scene where Burt and Spider take the cop car to go get help, after they back up from the group of zombies in the street. You can see a cameraman in the front passengers seat holding a camera with a blinking red light on his shoulder as they drive away.
Continuity mistake: In the scene where Captain Rhodes is first introduced. Initially, his captain insignia is horizontal (correctly). After a few shots in the same scene, his rank is now vertical.
Other mistake: When the fake TV ads for the Stuff are shown, the container states "1 Pint (.474ml)". 0.474ml is about an eyedropper drip of liquid. The decimal point shouldn't have been there.
Revealing mistake: When Jesse is cleaning out his room, he puts a tape into his tape player, and presses a button down on the top of it. But halfway though the scene of him packing his things away, you can clearly see the button is no longer pressed down, yet the tape still plays. (00:18:10 - 00:19:00)
Continuity mistake: In the beginning, when the two shuttles have docked together, one of the NASA astronauts inserts some kind of key into the door and begins to turn it. When he does you hear a ratcheting sound, however, once the door begins to open and there's a shot from the inside of the uninhabited shuttle, the astronaut isn't holding any type of tool, and still the ratcheting sound can be heard as the door opens further.
Factual error: The story takes place during spring of 1976 but Marty's parents drive a 1979 station wagon.
Continuity mistake: Near the end when the vampires are trying to get into the crypt and Jim Carrey has locked them out, we see two vampires trying to enter the room through one door and others going around to get in through the other entrance. When they get in, the vampires have reversed which entrance they were trying to use - the ones who stayed at the first door enter through the second door and vice versa.
Revealing mistake: In the scene where Herbert and Dan re-animate the dead corpse, watch closely when Herbert rams the little buzz saw into the corpse's chest. At the bottom of the screen, you can see where the fake chest ends.
Continuity mistake: When Jennifer finds the small boy, she removes a sheet from a mirror. In the next shot the sheet is draped back over the mirror again and then gone again. (01:35:50)
Revealing mistake: On the ledge Robert Hayes is attached to the wall by a wire protruding from his shirt.
Suggested correction: Not true, the ledge was only 2 feet off the ground.
Continuity mistake: The judge arrives and tells the audience that they can sit down. The guy on the left with a white linen shirt sits and crosses his left leg. Reverse shot, and he is repeating the action, this time crossing his right. (00:03:20)
Visible crew/equipment: At the end when the helicopter is hovering above the two guys fighting, we see the shadow of the camera on them multiple times.