Continuity mistake: Rumplestiltskin looks completely different in this movie than he did in the previous film Shrek The Third; Prince Charming momentarily talks to Rumplestiltskin in the tavern during the third film, and the character looks completely different, has a different voice and different demeanor.
Continuity mistake: During Andy's daydream at the beginning of the film, Mr. Potato Head has an eye patch over his left eye. When the daydream cuts back to reality we see that Andy has removed Mr. Potato Head's left eye to symbolize the eye patch. But when Andy's mum comes in with the video camera, his left eye is suddenly back in. (00:01:15 - 00:05:25)
Continuity mistake: When Alice leaves to think over Hamish's proposal and chases after the White Rabbit, the heels on her shoes change, but when she falls into the hole the heels are back once again.
Continuity mistake: When Xenophilius draws the Deathly Hallows symbol, he draws it so that the bottom of the line touches the bottom of the circle. The shot cuts away and back again when he draws the triangle, but the line is no longer touching the bottom of the circle. (01:49:40)
Continuity mistake: After being chased by soldiers after talking to his uncle, Dastan gets into a swordfight with Garsiv. As soon as it starts, Garsiv hits a pillar with his weapon knocking a significantly large chunk and a another smaller chunk out of it. In the immediate shot, the size and locations of the two chunks differ.
Factual error: They are present at Frankfurt, Germany. But with a closer look you see a cathedral at the right side. This cathedral and the central station are located in Cologne, Germany - they are about 220 km apart. (01:04:15)
Continuity mistake: When Lou and Nick are playing pool in the bar, Lou goes to break the rack and misses. When Nick goes to break them, the balls are racked in a different pattern. (00:50:10)
Factual error: The type of book that Eli is protecting would actually be just a fragment. The complete Bible, in braille, occupies as many as 18 volumes.
Plot hole: When Astrid gets on Toothless for the first time, Toothless takes off uncontrollably and tries to scare her. Hiccup seems to have no control over him at this time. How is that so if with the new tail fin, Toothless cannot fly without Hiccup's precise control of the tail fin? That whole sequence would have fallen apart. This mistake was even admitted to on the DVD commentary. (00:53:35)
Other mistake: Before the battle, the leader of the waterbenders says that he will have everyone extinguish as many sources of fire as possible. When the firebenders come up from the ground at the start of the battle, all of the torches lighting the city are lit.
Factual error: When Luke is playing video games in the camp he is using a Playstation controller, however when he pauses the game it shows a message telling him to push the 'B' button. 'B' buttons appear on Xbox games consoles rather than Playstations.
Continuity mistake: When Royce kills the Predator at the end, he slices the head off, and it falls backwards, and the body falls forwards. One of the next shots now shows the head to now be in front of the Predator body.
Continuity mistake: When Machete is picked up by Booth in the S-class, the car changes from an S500 to an older generation S-class, and then switches back for the rest of the film. The footage was from the trailer being edited in.
Continuity mistake: After the plane is docked Stallone and Statham enter the customs agency. Statham is wearing a camera on his neck with a small lens, he even shows it to the customs agent. After leaving the customs they walk across a square. The camera now has a big zoom lens attached to it. Statham is not wearing a lens bag. Where did he get that lens from? Also strange is that the lens is set in manual focus instead of automatic. Yet the picture stays focused even zooming in. This is not possible without looking at the screen. Plus the camera is turned off in the close up shot, with the image on the LCD composited in. (00:28:15 - 00:30:45)
Audio problem: When Scott fights Ramona's ex-girlfriend, Ramona holds his hands while punching her. One punch misses her but the sound of a punch is heard.
Other mistake: When the ride finishes, there is no sign of a safety bar in Gru's cart.
Continuity mistake: In the second scene where we first meet ranger Smith he is shuffling with some information pamphlets. When Ranger Jones yells his name he is startled and drops some of the pamphlets, but we can see that the last ones he put in were on their side. When the camera changes shots there appears to be some pamphlets sticking out. Then in the next shot they are gone. The pamphlets change locations between shots.
Continuity mistake: Baby Roberta spits a mouthful of half-chewed peas onto Ramona's face. In the immediate close-up, there is much more green mess on her face than in the preceding shot.
Factual error: When the people of Lilliput find Gulliver's boat, he picks up his cell phone and says he doesn't have any signal but has 11 messages and proceeds to listen to them. If you have no signal at all, you wouldn't be able to check your voice mail.
Continuity mistake: When Aron Ralston falls off the bike he is thrown few yards away of his bike into a bush. However, when he is taking the photo the bike is under his head.