Furious fans waged a social media war against the Marvel China promotion team for what they described as an unprofessional, embarrassing, and shambolic event on Thursday, prompting an official apology.

The event was held at Shanghai Disney Resort in honor of the 10th anniversary of the Marvel Cinematic Universe. Robert Downey Jr., Mark Ruffalo, Tom Holland, and Tom Hiddleston — who play Iron Man, The Hulk, Spider-Man, and Loki, respectively — were among the stars in attendance. But Chinese fans of the franchise complained that their beloved superheroes were pushed aside in favor of “irrelevant” local celebrities.

It is common practice for marketing companies to hire Chinese celebrities to promote foreign films screening on the mainland, and several singers who do not appear in the upcoming “Avengers” film have been hired for the movie’s advertising campaign.

On microblogging platform Weibo, the hashtag “Marvel China promo team apology” garnered more than 18 million reads, and at 6:18 p.m. on Friday, Marvel Studios apologized. “This event has failed everyone’s expectations,” the Weibo post read. “We take full responsibility and apologize sincerely to those who have always supported Marvel.”

Disgruntled fans, however, didn’t buy it. Most upvoted comments on the post said that they no longer trusted the China promotion team and demanded a more detailed explanation.

Chinese Marvel fans had been pumped for the star-studded event, with some crowds lining up outside the red-carpet area the previous day. Early Thursday morning, Marvel Studios advised fans on Weibo that the red-carpet area had reached capacity, and that any fans outside the area should watch the event’s livestreamed broadcast. Disappointed fans bombarded the post’s comments section, asking why organizers did not enforce their earlier rule banning crowds from lining up overnight.

Then at the main event, one line from the host, Natalie Wang, a former anchor for state broadcaster China Central Television, riled fans further.

“Would you like to step a little bit to the side?” Wang asked the A-list cast and crew onstage while introducing singers Zhang Jie and Eason Chan. On Weibo, fans slammed her for treating the stars rudely — though many had misheard her as saying “Would you mind stepping aside?” On Weibo, Wang also complimented the Marvel actors and directors for being gallant and welcoming to the local artists, who during the event had performed several songs that had no association with the Marvel universe.

In the final group photo from the event, Hong Kong star Eason Chan appears in the center, while Downey Jr. — who Chinese fans affectionately call “Nini” — stands to the side. Many fans found the photo heartbreaking in comparison with last year’s iconic “class photo” of the talent behind the franchise, in which the “Iron Man” star was front and center.

Some fans even went on Downey Jr.’s Instagram to apologize to the star on behalf of the Chinese people, out of concern that the event may have hurt his feelings. Others vowed to avenge the misdeed.

“Shanghai was a disaster,” one fan wrote in English. “There are tons of real fans in China questioning and scolding them now, and we will make sure that these people will make a better arrangement in the future!”

This article has been updated to include Marvel’s apology.

Contributions: Fan Liya; editor: Qian Jinghua.

(Header image: Chinese singer Chen Yixun speaks into the microphone as four Marvel stars stand idly by during the 10th anniversary event at Shanghai Disney Resort, Shanghai, April 9, 2018. VCG)