Star Wars: The Rise of Skywalker explicitly contradicted its own setup. By now it's pretty clear Lucasfilm never had a road map for the sequel trilogy. Although the studio briefly attempted to claim Palpatine was planned all along, that wasn't actually the case; Colin Trevorrow has admitted the Emperor's return was never part of his Star Wars 9 script. Rather, it seems to have been J.J. Abrams' idea, written in when he replaced Trevorrow as director.

All this means Star Wars: The Rise of Skywalker doesn't really fit with the rest of the sequel trilogy. Countless plot points were set up and dropped, simply because Abrams had no time for them; the most obvious is just how Maz Kanata acquired Luke Skywalker's old lightsaber. Previous tie-ins have been discarded or ignored; The Art of Star Wars: The Last Jedi confirmed that Luke Skywalker's old X-Wing had been destroyed on Ahch-To, and yet in Star Wars: The Rise of Skywalker it was able to fly without any repairs at all. These kind of continuity problems are frankly to be expected when you're making a story up as you go along. But, even more incredibly, The Rise of Skywalker even contradicted the tie-ins that were designed as part of its own setup.

Related: Star Wars: The Rise of Skywalker's Biggest Plot Holes

Every Star Wars movie is preceded by a range of tie-in novels and comics, usually marketed on their close relationship to the movie. But the "Journey to Star Wars: The Rise of Skywalker" feels awkward and uncomfortable when viewed in light of the film itself, to the extent most of the tie-ins are simply irrelevant. The worst problem, however, is with Rebecca Roanhorse's Resistance Reborn, which was designed to lie at the center of the entire pre-movie range. This novel explained why nobody came to help the Resistance in Star Wars: The Last Jedi. Roanhorse wove a fascinating narrative in which the Resistance learned the First Order had carefully prepared their attack upon the galaxy, sending agents out across the stars to identify potential Resistance sympathizers. At the very moment they launched their main attack, First Order agents across the entire galaxy were apprehending anyone they'd identified as a risk. Ironically, this plan backfired in the end because Maz Kanata located a list of potential Resistance sympathizers on Corellia, and the heroes were able to contact those who were still free and rescue many who weren't. That's supposed to be how Wedge Antilles got involved again.

There isn't a trace of this major arc in Star Wars: The Rise of Skywalker. Instead, Abrams suggests the Resistance has spent the last year licking its wounds, wondering why nobody came to their assistance. Poe desperately repeats Leia's strategy, sending Lando to issue a galactic-wide SOS, and this time it is answered. The film actually claims the only reason the galaxy didn't respond last time was they hadn't heard Leia's call for help at all; presumably the First Order was blocking her transmission all along. Star Wars: The Rise of Skywalker directly contradicts its own setup.

And this isn't an isolated example. Abrams drastically rewrote Poe Dameron's backstory, completely ignoring a wealth of tie-ins that had already fleshed it out in detail - ranging from novels to an actual Poe Dameron comic book series. Abrams seems to have intended to reinvent Poe as more of a scoundrel, giving him the kind of edge that made Han Solo universally loved, but in order to do so he contradicted everything Star Wars had done with Poe for the last four years. It's quite a remarkable decision, given Lucasfilm claimed everything counted in their new canon.

This is the problem with conducting a course-correction on the scale of Star Wars: The Rise of Skywalker. When you rewrite the story to such a dramatic extent so late in the game, you risk contradicting everything that's gone before. In this case, the scale of the problem is quite remarkable; it's one thing to contradict tie-ins from four years ago, another to fail to match with the books being written at the very same time you're shooting your film.

More: Star Wars: Rise of Skywalker Breaks Last Jedi's Plot In Its Opening Action Scene