This movie is not the catastrophe that EP7 was but it is pretty close. It tries to ignore Episode 8 and the parts that we good about that as much as possible and just goes back to nonsensical, timey-whimey stuff. Okay, in contrast to Doctor Who, it is not timey-whimey but you get the idea.

Again, it is utterly more important to achieve a particular moment or shot than to have any coherent narrative. Aside from the following points:

Ryan-SWI said:

Palpatine is back and it’s not explained how.

Kylo goes to find him and it’s not explained why he was looking for him, or how he knows he’s alive.

Snoke was a clone made by Palpatine. Not explained how or why, or anything more said on the matter.

Palpatine somehow has a whole fleet of Star Destroyers with Death Star guns on them. Not explained how.

Rey is a Palpatine, her Dad was Palpatine’s son (not explained how), so Rey is his granddaughter.

Rey and Kylo can both save people from death and bring them back to life. Not explained how.

Luke retconned from being a sad old suicidal man to “secretly” keeping tabs on Palpatine.

Luke and Leia retconned to “know” Rey was a Palpatine the entire time.

Leia dies, horrifically forced and poorly handled.

Han is in it as a “memory” (???). Makes no sense whatsoever, but then neither does anything in this stupid movie.

Palpatine shoots lightning at Rey, who deflects it back to Palpatine (Palpatine apparently decides that simply not shooting lightning anymore makes too much sense), then dies.

Ben almost dies. Then he comes back. Then he dies. But wait no not actually. Then he dies (for real this time).

Rey steals the Skywalker name.

Force ghost Luke and Leia. Both look horrific and Leia is clearly CGI. Because nothing shouts “respect” like CGI’ing the ghost of a dead actress into your film for cheap nostalgia brownie points.

which one of the posts above already compiled, I must also add:

multiple rather important plot-threads (that probably should have happened in JJ’s version of Ep8) are just dumped at you in the opening credits, including Palpatine
the movie confirms Leia was trained as a Jedi (yeah!) by Luke but actually, that is pretty irrelevant for the story… so WHY NOW? Maybe the idea is to explain that she is Rey’s mentor/master/teacher now but the movie goes nowhere with it (probably due to a lack of Carrie Fisher Material)
the Sith not only have a “hidden” world now, they also have a Mordor’s BlackSpeech-like Language and are retconned to a sort of satanistic cultist group
the General Hux character is suddenly a traitor, because he starts disliking Kylo… now. Not that he was treated differently by Snoke or anything. Also, he is little more than a “get out of jail for free”-card
JJ’s Knights of Ren are back, and they are basically 6 Klingon’s in Metal Armor and they do pretty much nothing the entire movie, until they annoy the now light-sided Ben Solo / Kylo in the final act. And we learn, wait for it, nothing about who they are…
the whole “child-soldier of the First Order”-thing is again, brought up for 15 seconds and than quickly forgotten again because facing an uncomfortable subject with any actual idea of what to do is not JJ’s idea of Star Wars
speaking of the first’s Storm Troopers, this movie establishes that Finn is not the only deserter (aka conditioning failure) but does absolutely nothing with it. Also, if an entire “regiment” basically stops following orders, why the hell are the space nazi’s not having bigger issues supressing the galaxy?
the First Order is defeated off-screen because “the people rise up” in a montage depicting two burning Star Destroyer ships, one crashing over Jakku and another being watched by freaking Ewoks
by the way, the First Order had large galaxy-controlling army and is utterly unaffected by the movie’s climax, but what the hell (in RotJ, they at least lost key personal and resources)
this movie’s Emperor can wipe out entire fleets with force lightning if he wants to, why did the Rebellion win again?
the Emperor’s new fleet is instantly killable once they do no longer receive data from the “navigation dish”, for some reason…

Not everything was bad, sound and music were good, the special effects are obviously great and the direction, cinematography and camera werestellar in many places. Daisy Ridley gives a great performance, considering the material.
The issue remains with script and plot. Problem is, if that fails you, your movie will always be a disaster, no matter what else you offer.

No amount of fan-editing can save this movie, similar to TFA.