Plot hole: Johnny's dad jumps in his truck and gets to Johnny in moments. That same journey was shown to be an overnight bus journey for everyone else.
Continuity mistake: While at Dino Stop, Katie convinces her dad not to play it safe and to take a chance to save the world. Rick agrees and extends his left hand for the "all hands, Mitchell family on three." In the closeup we see Katie put in her right hand, but in the wide shot Katie's left hand pulls out. Also, note that in the closeup both Katie's and Aaron's positions between their parents are switched. (00:45:00)
Factual error: Dwayne Johnson is pursuing a thief. He gets into a Porsche Taycan and pushed the start button, and he can drive off. But you have to have the key fob in your pocket or bag. Porsche explains: "As long as your key is close when you grab the door handle, the system automatically checks the encrypted access code on the key. Once your code is validated, the door will unlock, and you'll be granted access to your vehicle." Dwayne had no fob, as the car was just parked.
Continuity mistake: While Semmi is telling Akeem about their visits to the nightclubs, there are shots from the original movie with some women they meet. When the "woman" in red tells them she's going to tear them apart, Semmi's wearing a patterned shirt, tie, and blazer when he spits his drink. Two shots later (new footage), Semmi's shirt collar style changes, as well as the pattern on his shirt and blazer. (00:11:15)
Continuity mistake: When Mrs. Krementz talks with Zeffirelli while he's taking a bath and asks her to close the bathtub curtain, the cigarette he previously had in the mouth disappears in the next shot when Mrs. Krementz closes the curtain.
Revealing mistake: After Charlie talks to Emma in Francine's old bedroom and is standing in the doorway, the background (segment of the hallway) is obviously fake. Shown are less than five of the top steps on the staircase, only a fraction of the size of real steps. The lower section of the banister is also a reduced size. (01:31:35)
Other mistake: Packie arrived at Frank's garage on a bicycle, wearing a brown coat, hat, gray hooded sweatshirt, patterned shirt, and a T-shirt. Swaino arrived on a motorcycle, wearing a tight jacket, no hat, black gloves, and black jogging jacket with white trim. When they were outside by the grill, they had large sweaters over their coats. It isn't known where these sweaters came from. It can be assumed the blanket Swaino used at first was from Frank's garage, but the sweaters did not appear to be Frank's. (00:25:32 - 00:37:35)
Continuity mistake: Max Cameron's classroom appears to be slapped together and inconsistent. The wall is white but later tan. The door hinges are on the right, then left. The pencil sharpener, awkwardly mounted on the door frame, gets moved to the right. The hallway is a tan wall, but later just a closed door. Doors comprise the wall behind Dewey and there's a door behind Max, to the right of the white board. (00:59:55 - 01:00:43)
Continuity mistake: The angle of the laptop on the kitchen table changed (and no-one was close enough to have moved it). The laptop was initially more evenly aligned with the edge of the (round) table. A little later, the laptop was not visible, but probably should have been. (00:04:09 - 00:04:44)