Goofs

Continuity mistake with the rest of the saga present in all three sequels: the button igniting Luke's (formerly Anakin's) blue lightsaber is shown to be near the top of the hilt. In both the original trilogy and the prequel trilogy the button was in a different place, closer to the mid part of the hilt.

Near the beginning, Rey gives Leia her lightsaber. A couple minutes later there is a shot of Rey browsing the ancient Jedi texts, and the lightsaber is visible, attached to the left side of her belt. Two minutes later, Leia gives the lightsaber back to Rey.

When Rey is walking up the stairs to Luke's hut, her/ his lightsaber is hooked on the right side of her belt, suddenly, after a quick closeup of her face, it's suddenly in her pouch on the left side.

When Rey goes to the Death Star, it is only at the final climb to where the Imperial vault is that she has the lightsaber, seen now on her left side.

When Rey walks into the Imperial Vault on the Death Star, the door menacingly closes behind her. But in the light saber battle with herself, when she is startled she backs through what is now an open door.

When the Falcon Lightspeed skips, it would have remained safe after the first jump. TIE fighters lack a hyper-drive and therefore cannot enter Hyperspace. However it has been clarified before this movie that First Order TIE Fighters, unlike Imperial ones, do have a hyper-drive. However the TIE Fighters still wouldn't have been able to chase them, as the hyperspace tracking technology seen in The Last Jedi only worked from a capital ship such as Snoke's.

However later on, somehow Kylo Ren still manages to reach from Death Star 2 on Endor to the very far planet of Exegol on an Imperial Tie Fighter without Hyperdrive (it was not his First Order TIE Fighter, Rey stole that one from him), at the start of the film Darth Sidious said they had 16 hours before his attack and by the point they are on Death Star 2 many hours had went on.

Finn claims the second Battle of Endor was where the "last war ended". In actuality, in the canon expanded universe, the war went on for another year, culminating with the Battle of Jakku and the subsequent Imperial surrender. As Disney spearheaded their own expanded universe and undid all that had come before, it's odd they'd make this mistake. However, the Battle of Endor was effectively where the Empire was defeated by the Rebel Alliance, and the Emperor and Vader were both killed, thus closing the original trilogy. Further minor skirmishes with the remnants of the Empire in expanded universe spin-off materials don't count.

Throughout the final battle, the armada of Star Destroyers float above Exegol without any obvious downward thrust. Resistance ships are able to fly beneath them, uninterrupted by any force that is keeping them in the air, despite the planet obviously having a gravitational pull similar to that of Earth, judging by the manner in which Rey and Palpatine walk on its surface.

It is shown near the beginning of the film that Palpatine is in fact using the force to elevate and hold them in place.

It is unclear how a primitive race like the Ewoks defeated a Star Destroyer flying miles above them in space. Endor is not populated by humans. Ewoks do not know how to build spaceships, neither how to fly them.

Answer: The Ewoks never downed the star destroyer. They were merely watching it crash through the atmosphere. It still would be unexplained who destroyed that ship, if Endor doesn't have the military power for an air-strike. The only humans near Endor left the planet on the Millennium Falcon.

Lando says children of former Rebel Alliance heroes were kidnapped. However, none of the featured Rebel Alliance heroes is shown to have kidnapped sons, and the Resistance includes many non-kidnapped sons of Rebel Alliance heroes like Admiral Ackbar's son, Poe Dameron, Snap Wexley, etc. He is referring to people who are never mentioned specifically on-screen. While not technically a goof, this defeats the emotional impact.

Also as with Finn and Janah is revealed many of the storm-troopers were children kidnapped from their families at a young age and indoctrinated into the First Order. And despite of that neither of makes any effort to try to convince any First Order storm-troopers to deflect other than Hux (who was already a traitor by the point Finn asked him to deflect).

When C-3PO is saying, "If this mission fails..." on Kijimi, he is walking away from Babu Frik. The wires attached to his head are jerkily being hand-fed down through the ceiling to give him more distance.

The Emperors chamber and throne room, as seen in the fight between Darth Vader and Luke Skywalker in Star Wars: Episode VI - Return of the Jedi (1983), was at the top of an 800 foot tower with the only access being from an elevator; not in a corner penthouse with hallway access, as shown in this film.

The second Death Star is supposed to be over 100 km in diameter, and yet when the wreckage is found it visually appears to be much smaller.

Luke's X-wing is very badly damaged in Star Wars: Episode VIII - The Last Jedi (2017), as one of the wing panels is missing, because it's used as the door to Luke's hut. Yet somehow it's perfectly functional in this movie, after being left fully immersed in the sea and not maintained for ten years.

Klaud, the yellow slug alien, is the mechanic of the Millennium Falcon in the light-speed skipping sequence. Poe tells him he hopes he fixed the ship. However, the character has no arms, and he clearly can't reach or hold any mechanical tools required to fix things, much less reach them at the floor. Also, his impractical body can't reach hard-to-repair places. Given that Rose Tico was a mechanic that they trusted and could reach those places, it doesn't make sense that they choose the most impractical mechanic in the entire Resistance.

When BB-8 rolls forward to open the hatch on the command ship, Jannah says she'll cover him. She then proceeds to throw a grenade at a group of Sith Stormtroopers who were all facing and shooting the other way, not threatening them at all.

At the start of the movie Kylo Ren's small single passenger ship is shown making a dangerous trip to Exegol. But at the end of the film is shown the ships of average citizens reached the location without any problem, and even bigger ships like Leia's Tantative IV. Making the original trip seem incongruous.

The Death Star 2 had vaporized in Star Wars: Episode VI - Return of the Jedi (1983). There shouldn't be any debris.

On Kef Bir, the Millennium Falcon is landed by sideways ramming it into a hill, leaving a trail of destruction, due to the landing gear being defective. The Falcon however always had vertical take-off and landing capabilities, so this harsh landing is unnecessary.

Babu Frick wears a welding shield propped up on his head throughout the movie, but he never puts it down when he is actually working on C-3PO.

Finn's surprise that "They fly now!" is odd, since combatants on all sides in this Galaxy have been flying with jet packs frequently, going back at least to the Clone Wars.

At some point Rey mentions that the Sith dagger has done some terrible things, however the comment is odd since Rey somehow doesn't feel or say the same about her light-saber that she carries most of the film, and formerly belonged to Anakin Skywalker, which he used to do terrible things shown on-screen during his attack on Revenge of the Sith when he attacked the Jedi Temple, on his first mission as Darth Vader.