According to Business Insider, Instagram on Thursday started rolling out a major redesign to its interface that eliminated vertical scrolling. Users who had gotten the update quickly took to Twitter to express their displeasure about the change. It turns out that Instagram didn’t intend to roll out the update as widely as it did. Head of Instagram Adam Mosseri tweeted out an apology, stating that “this was supposed to be a very small test but we went broader than we anticipated.”