Dear Apple, this is the fourth time in a row one of your system upgrades on iOS or OS X make me loose a day or two - when it does not make me loose a lot of data - and I am fed up with it. My last experience with your High Sierra upgrade is truly shocking:

  • this morning, I decided to finally upgrade my eligible MacBookPro to High Sierra
  • I did it the right way, and everything initially seemed to work fine
  • then suddenly the installer stopped, announcing that "mac OS could not be installed on your computer" because "file OSInstall.mpkg was missing or damaged". Uuuuh???? What the hell?!? I was really scared since my backup missed two days of data, some of them being extremely important to me.
  • I tried the Recovery mode to install, no result
  • I tried to locate the missing file somewhere else in the installer's filesystem, no result
  • I tried the Disk Utility and it was worse since the app was struck with a spinning wheel...
  • I tried disk utils in the Terminal but my HD was gone. Just gone. Awful. I was so shaken I had to stay away from the computer for a few minutes.
  • then I discovered there are literally thousands of Mac users complaining about High Sierra's installer bricking their Mac with the same error... We're not speaking of a beta here, we're not speaking of something released yesterday. How can this remain broken?
  • fortunately, we have a few other Macs at home so I downloaded High Sierra from another one, downloaded the excellent and free Disk Creator to create a bootable USB version of the High Sierra installer
  • the install from that USB stick seemed to work and my data is still there, wooooof.

So for the visitor hitting this article and willing to upgrade a Mac to High Sierra, these are my VERY strong recommendations:

  1. full Time Machine backup first. Full. Mandatory. More than ever with the filesystem change. Make 100% sure your backup ended correctly and is usable. Do it, whatever the time cost.
  2. download High Sierra from the App Store but do NOT install; hit Cmd-Q to close the installer.
  3. download Disk Creator (link above) and create a bootable USB version of the High Sierra installer (located in your /Applications folder). Of course, you need a USB key...
  4. shut down your Mac ; insert your bootable USB key and reboot while pressing the Alt/Option key. At prompt, use the arrows and the CR key to select the USB bootable installer.
  5. install High Sierra on your disk that way and if it fails, use the Time Machine backup you fortunately did at step 1.

My Mac went bricked at 10am. All in all, it took me 6 hours and 36 minutes to find how to get it fixed, stop being scared of launching that process that could wipe all my HD out, and do it. Let's be very clear : this is totally unacceptable. The High Sierra installer is still broken and thousands of people are hit by that breakage.

On another hand, last Windows10 upgrade was so smooth it felt old-days-Apple, ahem.

I had to recommend my less geeky dad, kids, friends to avoid High Sierra's installer if I am not around. Wake up Apple, you're reaching unacceptable limits here. Your hardware starts sucking (incredibly noisy and ugly keyboard, bad touchpad design, useless and expensive touchbar, USB-C hell, no more SD slot) and some of your software are now below expectations. Wake up. Now!