Other mistake: There is a scene in which Piter DeVries is talking about the Landsraad (one of the governmental organizations in Dune). Twice he mispronounces the name, saying "Lansdraad" instead.
Factual error: When the world is celebrating the defeat of the visitors, it's daytime all over the planet.
Factual error: While the Leonov has a centrifugal section to simulate gravity, the ship's bridge is not part of it (evidenced by the stationary views outside its portholes). Yet in various scenes, including the one when Floyd rushes in to discuss his plan to return to Earth sooner with Tanya, gravity seems quite evident. Floyd marches across the compartment onto the raised pilot area's floor, then steps down from it, his foot landing audibly. Tanya's open jacket also hangs down normally as she moves about. Yet when Floyd demonstrates his plan using two pens, they float in mid air. (01:26:50)
Visible crew/equipment: At the end, when Sarah puts her glasses on, a light screen is reflected in them. (01:38:45)
Continuity mistake: The whole time sequence in the last part of the movie is messed up. After trying to nab the bad guys at the hotel, Tom Selleck goes home and puts his son to bed, then is called back in to work, and then the rest of the film is supposed to be the same evening, but it was already late night.
Revealing mistake: There's a scene where Dana's building is falling apart and stones and stuff are falling to the street below. One of the huge boulders bounces off a wooden police barricade in the bottom left hand corner of the screen, and then off a person. (01:29:14)
Continuity mistake: The first car he jacks is a white 4 door Oldsmobile Cutlass salon, and a 2 door Olds Cutlass Supreme in the next. (00:09:30)
Revealing mistake: There are two Ewoks Wicket's parent is in search of. One of the those Ewoks is climbing down a mountain and the other has finished climbing down. As this happens, look at the Ewok not climbing. As he bends down, half way down his left leg, there is some sort of fold there. This is mainly due to the fact that the Ewok actors wore costumes whilst filming. The fold is coming from the Ewok costume. (00:07:50)
Factual error: According to "The Doomsday Machine", full impulse drive is one-quarter the speed of light. In the first two movies, Enterprise used thrusters as opposed to impulse drive to leave Spacedock, confirming the notion that impulse drive is far too fast to leave such a (comparatively) small structure. Styles, however, orders Excelsior to one-quarter impulse, which is 18,750 km/s. In one second, she will travel half again Earth's diameter. From the time he gives the order to the time we see Excelsior clear spacedock's doors is approximately 40 seconds. Even allowing 30 seconds to go from rest to one quarter impulse, spacedock must be 13-15 times bigger than Earth! That's some serious engineering. (00:23:45)
Suggested correction: I reckon the writers always refer to levels of "impulse power" precisely so they don't have to worry too much about particular speeds (personally I always thought of it as roughly analogous to gears on a vehicle, but your mileage may vary). They use impulse to leave dock in both Star Trek II: The Wrath of Khan and Star Trek VI: The Undiscovered Country (it's implied to be unusual in both cases, for what it's worth). If all of that contradicts an earlier episode, I think we're looking at more of a retcon situation than a mistake.
Suggested correction: The warp scale has been adjusted several times, so it is impossible to say precisely how fast this fictional technology is, and by extension, how fast impulse is.
Impulse drive speed on starships have been consistent. Although sometimes quarter impulse on a shuttle refers to quarter power and not speed. Even if the speed of quarter impulse is 10 times slower than suggested (and used in the series), spacedock would still be 1.3-1.5 times bigger than Earth, which it wasn't. "It's fictional technology" is usually only a valid correction if the technology isn't explained in-universe. However, when certain parameters regarding fictional technology are established (even if they set wide parameters such as warp speed velocities) violations or contradictions (through bad script writing or whatnot) are valid mistakes.
Continuity mistake: At the beginning of the movie, Selena drives her car to the right side of the house. When the shot changes, the car is several feet further back and is now heading across the front of the entrance.
Continuity mistake: In the scene where Hector is talkin to Samantha and Regina in the radio station, just after they met, Hector is taking off his gloves. Then they switch over to the girls and when they switch back to Hector, his gloves are back on and he starts taking them off again.
Visible crew/equipment: When the Starcar lands for the second time, there is a shot where the car comes to a stop in front of the camera. In this shot, the wooden rafters of the sound stage can be seen. (Noted in the director's commentary).
Continuity mistake: After crashing through the guarded barrier of the base, David drives the stolen pickup truck and burning debris from the electrical storm falls onto the hood of the truck. In the next close-up the burning debris is shaped differently. Then after they crash through the wall, in the wide shot there is no burning debris on the hood. Yet, in the next close-up there's plenty of burning debris, but then in the next shot there is no burning debris again, just a smoking engine. The building debris surrounding the truck and behind it, in the first shot differs from all the building debris in the second shot as well. (01:21:50)
Visible crew/equipment: In the dinner scene in "Her" Excellency garden, right after Lamia breaks the egg in her hands, there's a cameraman's reflection on the metal jug held by Max.
Audio problem: When Winston says "Bugger." at the start of the film when he has the cigarette in his mouth, his lips are most definitely not in sync with the word. And it even sounds dubbed over.
Deliberate mistake: In the end sequence, when the joyous Valley of the Wind people run past Yuppa and the old woman to welcome back Nausicaä among the living, the same group(s) of people are seen twice running from the right to the left.
Revealing mistake: When Charlie sets the mens clothes on fire, burning gel is clearly visible on their clothes. (00:38:30)
Continuity mistake: When Daniel Stern takes Capt. Bosch down to the sewer area for the first time, the sweat, oil and dirt stains on his tank-top change constantly. This is most noticeable when they first descend into the cellar, where the shirt looks almost perfectly clean after being extremely dirty just a split second before as they start to climb down. Also, a little later, there's all of the sudden an enormous sweat stain on his chest that disappears later.
Factual error: When Jenny Hayden and Starman accidentally overshoot their destination and arrive in Las Vegas, Jenny discovers that her wallet is missing. She has no cash, no credit cards, and no identification whatsoever. The only money she has is a single quarter. Starman uses the quarter to hit the jackpot on a 25-cent slot machine, then uses the prize money to play the Horseshoe $500,000 slot machine, which he also wins. They then use the giant jackpot money to purchase a brand new Cadillac and drive it off the lot. Huge problem: In 1984 (and today), you could never collect a giant Las Vegas jackpot without several pieces of personal identification, for tax purposes. Likewise, you could never purchase and drive a brand new Cadillac off the lot without multiple pieces of identification and a financial disclosure statement (if paying cash).
Plot hole: When we first see the reanimated Sparky, his head's sewed on. While that makes him look a bit like the traditional Frankenstein monster, it doesn't make a lot of sense - the original monster had stitches on its neck because it was made from multiple body parts, but it's not like they sawed the dog's head off after it died...
Suggested correction: Do we ever see how much damage the car did?