Jason Goes to Hell: The Final Friday (1993) - 7 major mistakes

Visible crew/equipment: In the finale, Jessica runs over to Jason from behind and she stabs him in the heart with the dagger. Then Jason lashes back and hits Jessica, and she goes flying backwards. Absolutely anyone can see the large blue crash mat that she lands on.

Continuity: At the end of the movie the demons pull Jason down and he is tightly wearing his mask, but the next shot is his mask laying on the ground that Freddy comes back up to get.

Revealing: When Jason (in Robert's body) is shot in the head at the end of the hall, a close up reveals the bullet hole to be obviously just makeup.

Continuity: In the scene where Jessica is in the shower crying and the power goes out, she gets out, puts on a white t-shirt and goes walking around the house. When she walks through the garage door and grabs a hammer, there is blood on the front of the t-shirt (right at or a little lower than her waist and looks like someone grabbed the shirt with a bloody hand). Where did it come from? She didn't run into anything or anyone. [There's a deleted scene showing her step on a piece of glass. She gets blood on her hands when she pulls the glass out, then presumably wipes her hands on her shirt. Still a mistake, as removing that scene means the blood appears from nowhere, but there's the reason.]

Deliberate "mistake": If you watch closely, it is painfully obvious that in the beginning, when Jason is getting shot up, they are just repeating the same shot from different angles.

Revealing: When the female FBI agent falls over the railing onto the table, you can see that the legs have been pre-bent to make it break easier.

Other: In the scene at the beginning where Phil eats Jason's Heart, you'll notice that he screams like a monster for a bit. Don't you think that the two security guards would hear the screaming, being that they're in the very next room?