@jextxadore At least you can still download El Capitan to make a bootable installer. The problem I had was that Apple have removed Sierra from the App Store, so if you didn’t grab a copy beforehand, there’s no way to get back to it. I went to a local Apple repair place to get it reinstalled in the end, and then restored from a Time Machine backup, but for some reason, Safari extensions and plists didn’t all get restored.