X-Men movieverse inconsistencies and possible explanations.
Inconsistency: In X-Men (2000), Xavier says he met Erik at 17 but in First Class, they're both around 30.
Solution: They met just once/briefly when Xavier was 17 and they didn't meet again until First Class. The large gap might also explain why they don't recognise each other.
Inconsistency: In X-Men (2000), Xavier is confused why he can't use Cerebro (or his mind) to find Erik yet First Class shows the helmet taken from Shaw.
Solution: The helmet used in First Class was of a different design and was taken away after the JFK incident. Xavier was likely unaware that Erik managed to make a new version.
Inconsistency: The mansion in First Class looks different to that in the original trilogy.
Solution: Renovations were carried out due to the increasing number of students.
Inconsistency: In X-Men (2000), Xavier says Erik helped build Cerebro yet in First Class, it was built by Hank/the CIA and in DOFP, Hank says he built the facilities in the school with Xavier (Cerebro implied to be included).
Solution: Erik offered minor suggestions to improve Cerebro, some of which were included. Off-screen, obviously.
Inconsistency: In First Class, Moira MacTaggert appears to be close in age to Xavier and Erik yet in The Last Stand (44 years later), she looks just a few years older.
Solution: They are not actually the same character but just relatives, with Olivia Williams' version being younger, and the vastly differing careers can back this up. Alternatively, assuming both versions are the same, she managed to invent some sort of anti-aging technology after becoming a scientist/doctor.
Inconsistency: In the flashback (1986) in The Last Stand, Jean looks quote young (maybe around 10) but in Apocalypse (1983), she's 17.
Solution: The timeline change in DOFP affected her year of birth.
Inconsistency: In the same flashback and also in X-Men Origins, Xavier can walk and use his powers yet First Class shows he was paralysed in 1962 and DOFP shows that the serum takes his power to let him walk.
Solution: Over time, he managed to build a resistance to certain parts of the serum that takes his power. Alternatively, Hank remade the serum.
Inconsistency: In the Last Stand, a flashback of Angel in 1996 shows him as a young boy (anywhere from 10 to 13) yet in Apocalypse, he's a young adult.
Solution: The timeline change in DOFP affected his year of birth, just like Jean.
Inconsistency: In Logan, Xavier says he's 90 but First Class shows his year of birth to be 1932 so considering when Logan was set (2029), he should be 97.
Solution: Xavier had a degenerative brain disorder. Memory issues are understandable.
Inconsistency: In Logan, its stated that no new mutants have been born in North America after 2004 yet the 2023 ending of DOFP shows kids too young to have been born before then.
Solution: The younger kids are not from North America and maybe a few are humans bullied for having a mutant parent.
