The best-selling book series in history is still going strong following the publication of its final installment in 2007 — and for some, that’s part of the charm. J.K. Rowling, the author behind the seven-part “Harry Potter” children’s series, frequently adds to the lore of the series via Twitter. Most recently, she revealed that another one of her characters has a backstory that conveniently adds more diversity to Rowling’s beloved cast of characters.

Rowling is a perpetrator of retconning — retroactive continuity — or changing details of a literary work to change the continuity of the work. In changing her own canon to presumably incorporate more diversity into her writing, she’s not adding meaningful content, nor is she being respectful in how she’s introducing this supposed representation.

Fans of the series know Nagini as Voldemort’s loyal pet snake, whose soul he took away in place of a piece of his own. Now with the release of the trailer for “The Crimes of Grindelwald,” the second installment of the “Fantastic Beasts” franchise — a spin-off of the original “Harry Potter” series — it’s become clear that Nagini is actually a woman, as the character is played by South Korean actress Claudia Kim. She is a Maledictus, meaning she has a curse that solely affects women and forces her to turn into an animal for longer and longer periods of time until she is irreversibly that animal.

Rowling could have created a new character to be played by Kim instead of rewriting the backstory of an original animal character without considering the implications. For the first “Fantastic Beasts” movie, the majority of the new characters created for it were white.

Another problem with casting an Asian actress in the role of Nagini is that it plays into the stereotype that Asian women should be associated with mystical creatures. In casting Kim, the exact opposite of Rowling’s intention to retroactively diversify her series backfired by playing into harmful stereotypes.

The entire plot of the last book in the original “Harry Potter” series hinges on the fact that the heroes — largely white men — need to kill Nagini to defeat Voldemort. She is also the pet of a white man. These connotations are a step backwards, not a step forwards for diversity.

And Rowling seems insistent on digging herself deeper into a hole. In response to criticism of a Korean woman playing a snake named “Nagini,” Rowling tweeted Wednesday “The Naga are snake-like mythical creatures of Indonesian mythology, hence the name ‘Nagini.’ They are sometimes depicted as winged, sometimes as half-human, half-snake. Indonesia comprises a few hundred ethnic groups, including Javanese, Chinese and Betawi. Have a lovely day.”

What is problematic about this tweet is that it’s not the full story. “Nagini” is a Sanskrit word for a female goddess in the form of a snake, so if she really had to go forward with retconning the snake’s backstory, it would have been accurate to cast someone of Indian heritage, not Korean. Rowling has tried for diversity but gotten it wrong — she’s mixed distinct Asian cultures together into one heap.

This isn’t the first time Rowling has been criticized for ignorantly using other cultures to supplement the world she built in the series. After the publication of the series, she created another wizarding school in North America called Ilvermorny. She has been accused of misrepresenting Native American mythology to create the magic of the world without including characters representative of the native populations in the area. In response, she’s blocked or ignored her critics.

Rowling’s reaction to the backlash about turning Nagini into an Asian woman who is subjected to a terrible, monstrous curse is disappointingly similar. Rather than apologizing for her mistakes, she’s standing by an uninformed decision and tweeting out misinformation.

Once again, her retconning has failed.