Apple stopped signing iOS 11.3.1 on Friday, a move that prevents most iPhone and iPad users from downgrading their firmware to anything older than iOS 11.4.
iOS 11.4 was just released about a week ago, so this news shouldn’t come off as much of a surprise. Nevertheless, it’s sure to drum up some disappointment considering the likelihood that iOS 11.3.1 will gain jailbreak support thanks to a new tfp0 exploit released by security researcher Ian Beer.