Instagram has apologised after a test feature was accidentally rolled out to millions of users - with negative results.
The Facebook-owned photo sharing app was supposed to test a new change to its home page which saw users swiping sideways to see new posts rather than scrolling up and down as they had previously done.
But rather than selecting a small test area, Instagram accidentally rolled it out to millions of users, and quickly found that many were not happy with the change.
In a tweet, Instagram's head of product Adam Mosseri said: "Sorry about that, this was supposed to be a very small test but we went broader than we anticipated."
The change trended under the #instagramupdate hashtag on Twitter, accompanied by mostly negative comments.
Instagram quickly undid the change, reverting everyone's feed back to the vertical scrolling method, and as of the time of writing, it's unknown whether they plan to move forward with their horizontal method in the future.
The update comes after the company claimed in November that they are working on better ways for people to navigate the app and make it easier to connect with followers.
This means that people may notice things moving around on their page, but their images and videos will still remain on the grid.
They wrote: "Your profile is where you share who you are on Instagram, so starting today we're testing ways you can better express yourself and more easily connect with the people you care about on your profile.
"Over the next several weeks, you may see features re-arranged at the top of your profile including changes to icons, buttons and the way you navigate between tabs, which we hope will make profiles easier and cleaner to use."