The Lost World: Jurassic Park (1997)

Revealing mistake: When doing the scan on the T-Rex leg it's clear the Doppler isn't touching or even facing the dinosaur, but an image is shown on the screen.

Ssiscool

Other mistake: When they have the baby Rex and the parents approach for the infant, there's an outside shot of the T-Rex roaring as Ian moves away to the other side. After he does that the Rex on the other side silently roars, then that same roar bit is repeated from inside the trailer in the very next shot, but the roar is added in, showing repeated takes.

Continuity mistake: The tent scene in which Sarah and Kelly are sleeping, wrappers from cookies or food are in the first shot. When the angle changes the wrappers are gone, but Sarah hides the reappearance of the wrappers in the next shot. (01:18:50)

Audio problem: When the light towers are running in the base camp, the lights are on but the generators running the light can't be heard running. They look like AL4000 Terex list plants, diesel motors on the generators are super loud.

Continuity mistake: When we first see the remote for the cargo hold doors in the dead man's hand, the cord goes to the viewer's left and loops under itself. In the next shot the cord is going to the right and next to the ground so it can't loop under itself. In the next shot, the position changes again.

Continuity mistake: When Sarah screams in the camper when the T-Rex is by the window, she leans against the metal post with her back flat against it. We see a shot from outside and she's still screaming but doesn't move. The shot goes back to her in the camper and now her back is against the corner of the post.

Visible crew/equipment: In the trailer cliff scene when the rope comes undone, all three actors fall towards the bottom and certain death. The actor/stunt man to the right is harnessed and, to top it off, his hands never grab the ledge. (01:02:40)

Continuity mistake: When the girl meets the mini dinosaur she is standing on the sand, parallel to the edge of the grass. A frame later she's half a meter away, perpendicular to the grass. (00:02:50)

Sacha

Continuity mistake: When Dieter Stark is about to taze the dinosaur, the guy with the long beard approaches him, telling him what it is. As the bearded man says "They're presumed to be scavengers, like jackals", Stark's taser is closed mostly inwards. In the next shot, the taser is suddenly extended, opened out.

Factual error: There is no way that the SS Venture could plow into the dock as depicted. Easily pulling a 30-foot draft, the Venture would have grounded out a mile away from the shoreline, unless the ocean was 30 feet deep right off the beach.

Revealing mistake: When the dinosaurs are released from their cages and are running around the camp, a jeep is launched into the air and lands almost on top of the 2 hunters who leap from the tree. When the jeep falls forward, and down out of the tree the bottom of the tree moves and shakes in a way it shouldn't if it was truly made of wood.