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 Serabi or any of the other lions on the numerous times he spoke with them, exposing Scar.
Continuity mistake: When Anna's singing "The next right thing" she puts a bag on her shoulder, with the strap on top of her hair. After the camera spins round her, her hair is suddenly on top of the strap. This bears a strong similarity to the mistake in the original Frozen where Elsa's hair passes through her shoulder - might be a deliberate nod, or else animating hair around objects is difficult enough that shortcuts are often taken.
Factual error: With a number of flowers blooming, the movie appears take place in spring. There are many scenes of central park with flowering trees and shrubs in full bloom. However, the yellow blooming shrubs called forsythia do not bloom at the same time as the flowering cherry trees. Forsythias bloom about a month earlier than cherries and are usually the first items to bloom in spring.
Continuity mistake: The two cucumber slices that Jesper puts in the palm of the Drill Sergeant change position between shots - in particular, in the close-up with Jesper walking away and putting the teacup in his hand as well, the two slices are side by side, while they are instead one on top of the other before and after. (00:02:25)
Other mistake: When the characters go to the Himalayas, the whole time, like for 20 mins, including the confrontation scene, they are all wearing casual, short-sleeved shirts. You can see Mr. Burnish's henchmen wearing winter clothing, while the main characters don't freeze to death. They only start getting cold after a long time.
Factual error: Towards the end of the movie when Superman and Henshaw are fighting on the Watch Tower in space, Lois hits the sun shades to lower them so that direct sunlight can hit Superman and power him up. This is out in space with no atmosphere to filter the sunlight. The reason the blockers were there was for this reason, to keep the harmful unfiltered sun light from hitting people on the ship through the windows. However, she is able to stand there in the direct light after it's done and kiss and hold Superman without being hurt or burned by the intense direct unfiltered sunlight or its radiation.
Continuity mistake: After the alien abduction, Emmet plans to lead a rescue mission and opens the gate asking "Who's coming with me?" During the sequence, the shadows change completely. At first he is not casting much of a shadow, then it reaches the metal doors, then it stops midway towards it. (00:20:55)
Factual error: A blunderbuss is fired at a safe. The shot not only bores a hole into the safe but also blasts it out of the window behind it. First, a gun can do no such thing; a cannon can. (The film already establishes that the safe is incredibly heavy.) Second, the hole on the safe is wrong. It is gouged outward as if by an explosion from within. (00:38:10)
Continuity mistake: The protagonists escaped from captivity and managed to return to Harry's palace. Luka decides to leave to go look for his mother. Harry seems to send him off, and he is standing in the middle of the stairs, about 4 steps below the guard. Harry at this point is in close-up; the guard is not visible, and at the next cut somehow Harry shoves him off as if he were standing directly behind him. (00:16:00)