SALT LAKE CITY — Moviegoers expressed frustration late last month over “Olaf’s Frozen Adventure,” a 21-minute short film that played before Pixar’s recent film “Coco.”

And now, critics are retrospectively investigating what went wrong with the short.

Though “Coco” earned $402 million at the box office worldwide and earned rave reviews, the Olaf opening short did not sit well with critics or fans. People said they hated the short film because it ran too long and didn’t have the heart and soul that other Pixar shorts have had in the past. It even received a 36 percent from audience members on Rotten Tomatoes. In fact, Mexico started cutting it from theaters due to the outrage.

Pixar and Disney have since removed the short film from all "Coco" showings, according to Mashable. The removal began Dec. 8.

Vox’s Alissa Wilkinson wrote a retrospective look at why the short film sparked controversy and flopped, despite the popularity of "Frozen."

For one, few saw the lengthy short film coming, she wrote. Moviegoers didn’t expect to see a 21-minute film before “Coco." Some viewers expressed worry that they attended the wrong movie because Olaf's short ran so long.

“Most anyone who’s seen a Pixar film knows they’ll see a short before the film — that’s not the problem,” Wilkinson wrote. “And if 'Olaf’s Frozen Adventure' were, say, four and a half minutes long, even those who are sick to death of 'Frozen' would probably have forgotten about it by the time 'Coco' was over. But if you’re not prepared for that 21-minute runtime, 'Olaf’s Frozen Adventure' feels interminable, as if it will never end.”

Wilkinson wrote that the short film's origins also posed a problem. It was meant for TV, which didn't translate well into cinema.

Indeed, “Olaf’s Frozen Adventure” began as a concept for a TV holiday special set to air on ABC. But Disney and Pixar later dropped it in favor of putting it before “Coco," a decision they made in June.

Advertising and promotion are another reason the short film wasn't well received. According to Mashable, some consider the “Frozen” short to be Disney self-promotion. Critics said Disney took advantage of Pixar's trust with the audience to promote its own material.

To their credit, Disney did let audiences know that "Olaf's Frozen Adventure" was coming. Back in June, Disney announced that the short film would play before “Coco,” even mentioning that the adventure story would be 21 minutes, according to the Deseret News.

“It’s a perfect pairing," said John Lasseter, chief creative officer for Disney/Pixar animation, to USA Today at the time. "They’re both beautiful, heartfelt films about families and how people carry traditions forward. I can’t wait for audiences to get to see both of these terrific projects together on the big screen.”

Ultimately, fans won’t have to worry about the film anymore, and it serves as a learning lesson for Disney moving forward.

“Meanwhile, audiences in the U.S. no longer have to contend with 'Olaf’s Frozen Adventure' if they go to see 'Coco' — and that’s a good thing. 'Coco' is plenty capable of standing on its own as an enjoyable, beautiful film. No snowmen are necessary,” Wilkinson wrote.