Plot hole: If Bradley Cooper was able to "quintuple" his money every day in the market as he claims to have done, he would have been able to earn the $100k he borrowed from a loan shark within a few days, starting from $800. Alternatively, he is shown in one scene winning a pot in poker where he could presumably also make a large amount of "seed" money from gambling. There was no need to borrow such a small sum of money from a loan shark, making the entire sub-plot unnecessary.
Deliberate mistake: In the final shot of the film, Jill's head moves slightly when she's supposed to be dead. In the commentary, Wes Craven confirmed this wasn't strictly intentional, but he decided to leave the take in on purpose in case he decided to bring her back in a future installment. But unless a sequel proves she's still alive, it's technically a mistake, albeit a deliberate one.
Factual error: Winter in Antarctica would not have a night and day as portrayed, with the amount of light changing so much during the course of 24 hours.
Factual error: In the scene straight after the opening credits we are taken to Baker Street where construction work is being done. This work is identified by a sign with a logo as being for the underground line. The logo type face was developed by a Mr. Edward Johnston for London Underground from 1913 but the distinctive typeface used in the film was not in place until 1919. This is obviously long after the 1891 setting of the film.
Continuity mistake: There is a scene where Hugo is on the station and sees a key down on the tracks. There are two separate shots of the key and both times it is buried in the stones next to a sleeper. Then Hugo jumps down onto the tracks to pick it up and its now sat on the middle of the sleeper when he picks it up. (01:22:30 - 01:23:10)
Character mistake: When the EMTs are resuscitating Dr. Harris, they use a defibrillator despite their being on a wet metal dock. Not only is this highly dangerous to absolutely everyone present, it would be completely ineffective at restarting his heart as the water and the metal would dissipate the electric current too much for it to do any good. At the very least, they would have stabilized his spine then moved him to a dry surface before beginning defibrillation. (00:08:30 - 00:09:10)
Suggested correction: External defibrillators are self grounded and so can be safely used on wet or metal surfaces. https://danboater.org/travel-health-and-safety/are-aeds-safe-to-use-in-wet-environments.html.
AEDs are indeed safe to use in wet areas - but in the film, it is not an AED that is used. AEDs are automated, and not operated by humans, so as to reduce risk. Your link explicitly states the rescuer must not have direct contact with the body: they just apply the pads, then move back. In the film, it is shown in detail that the medic applies the paddles and then operates them while still in contact with the body. The mistake stands: it's a traditional defibrillator, thus incorrectly used.
Revealing mistake: While driving the Mercedes to the house of grandma, the gauges on the dashboard show speed is zero and the engine is cold.
Continuity mistake: In the restaurant scene Nathan has a glass in his right hand on the table. The next shot appears the glass on the table without his hand, and then again in Nathan's hand.
Continuity mistake: The overall timeline of the film is about twelve months but it is inconsistent as far as the seasons. When Blomkvist arrives at the Vanger's island, it is the dead of winter with deep snowfall. A short while later, when Blomkvist is talking to the detective on a pay phone (who asks if he is surviving the winter weather), the snow is gone and the deciduous trees have no leaves, but a few minutes later, when the scene cuts to Henrik Vanger being rushed to the hospital, it is suddenly the middle of summer, sunny and the trees are in full bloom. When Lisbeth arrives on the island, and she and Blomkvist are sitting outside at night talking, the trees close to the house are bare and a howling wind can be heard in the background, but the next day trees have leaves. Some weeks later, when Lisbeth saves Bloomkvist from Martin, it is winter again, with heavy frost on the ground and trees are bare once more. A little while after that, when Lisbeth and Blomkvist go to find Harriet, trees on the street are in full bloom. A day or two later, when Blomkvist is talking to Harriet in the park, it is apparently now early spring because the smaller deciduous trees are only just beginning to sprout new leaves while some bigger ones have none at all. At the very end, it's just before Christmas again.
Factual error: Near the end of the movie, when they go to steal the boat, there is a Puerto Rican flag in the front of the boat. This flag has the royal blue triangle, instead of the light blue that would have been in the 1960's such as all the other big flags used on poles.
Continuity mistake: When Justin gets a text from Mike's cell phone, it shows a close up of the screen. In the "to" box, it says Nikki although it's Mike's phone.
Continuity mistake: When Valerie's father was the werewolf, his right paw was burnt. Then, when we see the hand later, there isn't a scratch on it, but again later, we see that it is, once again, looking burnt.
Plot hole: The very last scene shows Mary building a wall, apparently in her belfry. But there should still be the original wall that Rose built, with the hole in it that Mary smashed in. By killing Rose / having killed Rose, she prevents further harm, but all effects that took place before that (also the building of the wall), should stay (like her scars). It is very unlikely Mary broke down the whole wall just to add another body. (01:28:25)
Other mistake: In the scene near the start as Will Atenton is being driven to his house by the property agent there is a close up of the car which shows a snow covered bonnet therefore the car would not have been driven very far as the engine was not warm.
Other mistake: In the hospital, Barrett had his right arm in a sling and his lower left leg in a cast. When the police/ detectives were trying to find Barrett, one detective said Barrett could not have driven himself somewhere because he had "a cast on his leg." The cast was on the left leg, so Barrett could have driven using his right leg, as usual. Maybe he couldn't have driven with a cast on his right arm, but the detective gave the wrong location of the leg cast. (00:50:30 - 01:13:45)
Continuity mistake: When Paul is chasing Bozlovski at the port, he repeatedly shoots through his passenger side glass, destroying it. A few seconds later, the glass can be seen undamaged when both cars are banging each other.
Continuity mistake: The licence plate of the Toyota Camry that Dagny Taggart is driving changes from a red Colorado plate to a Wyoming plate. (01:25:26 - 01:26:45)
Revealing mistake: When Donovan witnesses a fatal traffic accident on a rainy night, he suffers a mild heart attack and collapses in the street. Although he's lying on his back, unprotected from the downpour, surrounded by rain striking the pavement in both foreground and background, closeups show that no rain strikes his face, his felt hat, or his clothing. (00:12:20 - 00:12:50)
Revealing mistake: When Anna's looking at her reflection in the mirror she starts rubbing her face vigorously. Look at her right cheek and you'll it's red before she rubs, result of multiple takes.
Suggested correction: The main character says he did quintuple his money four days in a row, not that he could continue to do so. "Presumably" he could do anything, like robbing a bank. Gambling is not a secure source of income, even with knowledge of the odds and every tell, he could also lose a lot of money.