Plot hole: Scar tells the pack he didn't make it to the gorge in time to help Mufasa. However Zazu was with them at at the gorge. He could have easily told Sarabi or any of the other lions on the numerous times he spoke with them, exposing Scar.
Suggested correction: Actually, Zazu wouldn't honestly say that Scar was lying; he left Scar at the gorge, but for all he knows, when Scar talks about not getting to the gorge in time, Scar could just mean that he couldn't find a safe path into the gorge to help Mufasa and Simba escape.
Suggested correction: Zazu wasn't with them when Scar said so. He was with Rafiki. He couldn't have heard what Scar was saying.
Suggested correction: But it wouldn't have confirmed that he killed Mufasa.
It would prove that Scar (who had the most to gain from Mufasa and Simba's deaths) was lying about the circumstances surrounding their deaths. But no-one brings it up.
It would prove Scar is lying about the events of Mufasa's (and Simba's presumed) death, and given Scar gained the most from it, the other animals should be extremely suspicious of him.
Continuity mistake: In the scene where Stanley and Zero are digging to find the chest toward the end of the movie, the background behind them is just a dirt wall. In a following shot upon discovering the box, there are stairs that lead to the hole. In the next shot, these stairs are gone again and it's just the hole again. (01:38:05)
Factual error: In the beginning of the film, the Dowager Empress Marie states that the year is 1916 and that they are celebrating the 300th anniversary of their family's rule. The 300th anniversary actually took place in 1913. (00:01:05)
Revealing mistake: After Nuclear Man destroys the cab's hood, the shot changes and there's a thick string running behind him all along the car, and the cab driver is stretching out to pull it. Probably he was activating some sort of bad FX.
Factual error: A toy modern four-door automobile and a clear plastic ball can be seen as the children play when the Burgermeister comes in on his wheelchair. Both unlikely for a story set (presumably) in the 1800's, at the latest.
Continuity mistake: When the Love stone is rolling toward Lawanda, she puts up her left hand in an attempt to stop it. In the next shot, she is holding up her right hand. When the stone hits her, she is holding her left hand up again.
Continuity mistake: When Nora is explaining to her friends at lunch that she and Luther are skipping Christmas, her friend asks her "When do you leave?" without Nora ever mentioning that she and Luther were going on a cruise.
Other mistake: In the intro to the Pastoral Symphony, the narrator identifies the deity who cloaks the world with Night to be Morpheus, who is the Greek god of sleep and dreams. However, the character in the animation is fairly obviously female, with long hair, eye shadow, and lipstick. My theory is that the character was intended by the art team to be Nyx, the Greek goddess of Night. Night would be a more likely candidate to be making it nighttime across the world, while Morpheus would be more likely to put people to sleep or send them dreams.
Suggested correction: Without further evidence/proof, this theory remains just that. A theory.
Continuity mistake: When Kuzco and Yzma make a dive for the potion bottle, Yzma is turned into a cat simply by landing on the potion bottle. This suggests that a person only needs to touch the potion in order to be affected. However, when Kronk and Yzma are serving Kuzco dinner and are trying to avoid poisoning themselves, Kronk pours his potion drink on himself and is not affected.
Factual error: A theater marquee is visible promoting the showing of a film called Tribeca Follies. The acronym "Tribeca" - an amalgamation of "Triangle Below Canal [Street]" - didn't come into usage until the 1970s.
Continuity mistake: When Barry gets stuck inside for the first time, he hangs onto the drapes. His arm is straight across, but in the shot behind him, his arm is now bent and raised and above his head.
Plot hole: In the Cowboys' last possession of the final game, Spike makes a long run before being stopped on the goal line. The Cowboys' next play is a run up the middle. The Little Giants stop the run and the Cowboys lose possession, but since that was the first possession of a new set of downs, the Cowboys would have three more chances to score.
Other mistake: In the music within the ending credits, the lyrics incorrectly state that Raph is the leader of the group when all Turtle fans past and present know it is Leo.
Continuity mistake: At the beginning of the movie, Itchy comes to heaven in a teal colored shirt. When given a halo, he is in a blue shirt (the shirt is for heaven, but not given to him at that moment). When Itchy runs to Charlie right after that, his shirt is teal again. When Charlie tells Itchy he is dead, that's when the shirt changes to blue again (purposely).
Continuity mistake: Near the end after the mob goes over the cliff and Jim is chasing the horses through a snow patch, another rider on a light colored horse can be seen on the right. (01:36:00)
Audio problem: On the first level of the video game, after Velma brings up what she remembers what Eric said about the Scooby snacks in the game, you hear Daphne talking but you see Velma's lips moving. (00:01:00)
Continuity mistake: In the scene where Grug is chasing after Guy, they both wind up stuck in a tar pit. After successfully escaping they are covered in tar and Grug even gets himself stuck to Guy. In the next scene everyone is running from the exploding ground up between the mountains and both Grug and Guy are completely clean and free of tar.
Continuity mistake: Lotte barges in the pizza place and carves her name onto Shaggy and Scooby with her sharp nails. LOTT on Shaggy's shirt, and the E in Scooby's fur. They run out the door and then come back to pay for their food. Suddenly the rips in Shaggy's shirt and the scraped off fur on Scooby's chest have vanished. (00:23:45)
Audio problem: During the Tea Party scene, the Mad Hatter and March Hare ask Alice to tell her story. After the Mad Hatter says "And when you come to the end, stop!" audio follows of the voice director saying "great," leftover from the original recording. (00:45:40)