History ChuckCunninghamSyndrome / Film

** The series is rather infamous for its failure to retain leading actresses — not because the characters were disliked or there were problems on set, but because the actresses in question simply haven't been available to return for subsequent films. Notably, [[Creator/ThandiweNewton Nyah]] from [[Film/MissionImpossibleII the second movie]], [[Creator/MaggieQ Zhen Lei]] from [[Film/MissionImpossibleIII the third movie]], and [[Creator/PaulaPatton Jane Carter]] from [[Film/MissionImpossibleGhostProtocol the fourth movie]] disappeared from the franchise inexplicably. It wasn't until [[Creator/RebeccaFerguson Ilsa]], who debuted in ''[[Film/MissionImpossibleRogueNation Rogue Nation]]'' and reprised her role in [[Film/MissionImpossibleFallout two]] [[Film/MissionImpossibleDeadReckoningPartOne more films]], that the series actually managed to keep a leading actress on an ongoing basis.

* ''WesternAnimation/RalphBreaksTheInternet'' notably has [[Characters/SuperMarioBrosBowser Bowser]], who previously appeared in ''WesternAnimation/WreckItRalph'', but is absent from the film without even a mention or explanation as to why. This was because Creator/{{Universal}} acquired the movie rights to the ''[[Franchise/SuperMarioBros Super Mario]]'' franchise from Creator/{{Nintendo}} almost a year prior to its release. [[Franchise/SonicTheHedgehog Sonic and Dr. Eggman]], both of whom also appeared in the prior movie, ''[[SubvertedTrope did]]'' return for ''Ralph Breaks the Internet'' despite also having [[Film/SonicTheHedgehog2020 a movie]] in production by a different company by then.

* Lori from ''Film/{{Ted}}'' was built up as John's major love interest and motivation for him to grow up. In the sequel, they've apparently divorced after only 6 months of marriage and John is now chasing his attorney, who just so happens to be [[SatelliteLoveInterest an attractive young woman who doesn't try to change him]].

* This happens in the ''Film/{{Night at the Museum}}'' franchise as well with Creator/CarlaGugino's character Rebecca Hutman, who despite playing a pivotal role in the first film from 2006, mysteriously and suddenly vanishes from the sequels for no given reason. With ''Battle of the Smithsonian'', the second film from 2009, it would have made sense for her not to appear seeing as we already had Creator/AmyAdams as SuspiciouslySimilarSubstitute Amelia Earhart, and it would have been complicated for Gugino and Adams' characters to make a love triangle with Larry, and Gugino was likely filming ''Film/RaceToWitchMountain'' around the same time this movie was being made, so it would have made sense for her not to return for the second film, anyway. Though she ''could'' have suitably returned in the franchise's third film ''Secret of the Tomb'', released in 2014 (heck, even the BigBadDuumvirate from the first film [[TheBusCameBack returned!]]), but Gugino was probably busy finishing up filming the first season of ''Series/WaywardPines'' which was still being filmed when this movie started filming, and the screenplay was already written, so it was too late for her to even negotiate a deal to return, anyway. Her character's absence was never even acknowledged at all in the sequels, nor is she even mentioned or seen again, but if there were an InUniverse explanation, it's likely that her character quit her job as the docent of the museum (probably out of protest against most of the exhibits being moved to the Smithsonian Museum in the second film, and her love for history being ruined for her as a result) and/or she moved away (but then again, this is never even acknowledged in neither sequel). Ditto for Amy Adams' [[ActingForTwo other character]] Tess, who first shows up at the end of the second film as the museum's new docent, but is herself mysteriously absent nor is she ever acknowledged in ''Secret of the Tomb'' (which, unlike Gugino's case, does not make any sense as Adams had a free schedule and therefore could have showed up, and her character's the new docent, but it's likely she probably wasn't interested in returning for a sequel, though if she ''did'' return, it probably would have been another case of SuspiciouslySimilarSubstitute to compensate for Carla Gugino's character's absence, or she would have at least appeared in TheCameo).

* Dana Freeling, the eldest daughter in ''Film/{{Poltergeist|1982}}'' is completely absent from the film's sequel, with only a small mention from Steven that she wouldn't return to the original house. An original draft of the script explains her absence due to being away at college. Tragically, this is due to the actress, Dominique Dunne, being murdered by her ex-boyfriend shortly after the release of the first film.

* ''Film/AmericanPie'' and ''Film/AmericanPie2'' center around four friends; Jim, Kevin, Finch, and Oz. In ''Film/AmericanWedding'', Oz is completely left out. You'd think they'd at least mention why one of Jim's best friends didn't attend his wedding. He returns for Reunion though.