Of course this had to happen on Sex On Phonea Monday.

Instagram users were unable to upload new photos and videos to their Stories for several hours on Monday and it definitely wasn't OK.

Instagram confirmed the issue in a tweet Monday, saying that a "bug" is "preventing some people from uploading to Instagram."

We're aware of a bug that may be preventing some people from uploading to Instagram. We're working on a fix.

— Instagram (@instagram) May 1, 2017

The issue, which cropped up for both iOS and Android users, appeared to primarily affect uploads to Stories, though users were also having issues uploading videos to their main feed. Instagram didn't initially elaborate on the source of the issue or when a fix would be in place, but the issue appears to have coincided with an app update also released Monday.

Meanwhile, Instagram users were -- of course -- not pleased with Instagram's technical issues.

With Instagram stories down, looks like I'm headed back to Snapchat!

— Jordan Hart (@jordanhart) May 1, 2017

Breaking News: Instagram stories is down. In related news, Snapchat celebrating a special occasion. #instagramdown pic.twitter.com/v4C9eMaZSK

— Toby Nwabuogor (@Toby4WARD) May 1, 2017

Instagram won't let me post my stories and we're all suffering.

— Momma Duh (@msduh) May 1, 2017

Instagram stories is down. pic.twitter.com/J8vD3fdYoF

— Coti Howell (@CotiHowell) May 1, 2017

Are @instagram stories down? Haven’t been able to post all day

— Victor Lares (@vanderbiest_) May 1, 2017

RIP INSTAGRAM STORIES

— Orsola Scarano (@Queen_Orsy) May 1, 2017

That sucks!!! Took so many adorable kitty videos to post on Instagram stories and all of them keep saying upload fail. Wtf? 😡

— AdamGoesHam (@AdamGoesHam) May 1, 2017

Yoooo @instagram, what's going on with the Insta stories?!? Nothing is getting posted & it keeps saying, upload failed & try again!

— James Padgè (@YourBoiFatz) May 1, 2017

Why won't Instagram let me upload stories! 😭 anyone else having this issue? #thegirlgang

— Rebecca Tudor (@RebeccaLaura) May 1, 2017

The strong reaction shouldn't be surprising, though, given the sheer dominance of Instagram Stories, which has 200 million monthly active users, according to the company.

UPDATE: May 1, 2017, 5:18 p.m. PDT An Instagram spokesperson confirms the bug has now been fixed.