“This advertisement is disgusting and never should have appeared on our service,” a spokesperson for Snapchat said. “We are so sorry we made the terrible mistake of allowing it through our review process. We are investigating how that happened so that we can make sure it never happens again.”

The ad was for a game called “Would You Rather?!,” which was created last year by Daniel Lulic, a developer who previously designed two mobile “Truth or Dare” games. In Apple’s App Store, several reviewers criticized “Would You Rather?!” for posing questions about rape. “I am very disturbed with one of the would you rather questions,” wrote one user. “It’s under humor and it says Would you rather: Get raped by a llama or Rape a llama. No! Rape is NOT a joke!”

The advertiser has now been blocked from Snapchat, according to the company.

In February, Snapchat opened its advertising platform so third-parties can build software to buy ads, further automating the company’s advertising system. In its guidelines, Snapchat says that “all ads are subject to our review and approval.” The official policy prohibits an array of content including anything that is “shocking, sensational or disrespectful.”

This most recent debacle sent the stock price of Snap Inc., which owns Snapchat, down more than 4 percent. The price jumped last month after an earnings report that exceeded expectations for the fourth quarter of 2017. Snapchat has been struggling since it went public last March, reporting dismal financial results last year for three consecutive quarters. Last week, Snap Inc. announced that it will be cutting 120 engineers.

The company relies on a patina of cool to keep its young user base engaged, even as other mobile apps with similar or competing features have risen in popularity. Influencers play a large role in Snapchat’s branding, and the stock fluctuates based on their behavior. Last month, Kylie Jenner, who has marketed her cosmetics line on the platform and is one of its most popular users, tweeted, “does anyone else not open Snapchat anymore? Or is it just me … ugh this is so sad.” Her comment has been liked more than 377,000 times. The day of her tweet, the company’s stock dropped 7 percent.