I am trying to boot into my mac and it's taking me into macOS Utilities. I selected the reinstall macOS option, I do the eligibility check, that works. Then I select the hard drive to install it on (OS X base System). However as soon as it starts, the install fails with an "Error occurred while preparing the installation try again." I tried the date fix as many people suggested but that didn't seem to work. What else can I try?


Added images with result of commands

enter image description here

enter image description here

  • I only have OS X base Systems.
    – Niana
    Jul 17, 2017 at 16:55
  • @klanomath When I open disk utility I have Apple SSD SM0256f Media. and its filled with the OS x base system
    – Niana
    Jul 17, 2017 at 16:57
  • @klanomath Took me a while, terminal suddenly didnt want to show up in the menu. The first screenshot went down to disk16, however I can only post two images because of my reputation.
    – Niana
    Jul 17, 2017 at 18:37
  • @klanomath How do proceed?
    – Niana
    Jul 17, 2017 at 18:56
  • @klanomath YES! just finished. I dont think im seeing any files thou. Still want to Teamviewer in?
    – Niana
    Jul 18, 2017 at 12:51

1 Answer 1


The previous content of the main volume has been replaced with the content of the BaseSystem.dmg in the Recovery HD by unfortunate circumstances. These circumstances are unclear. Some files have been recovered with the usual tools to an external volume.

To reinstall macOS do the following (all data on your Mac will be erased so don't proceed if you still have some data on your main volume/disk or if you want to recover it!):

  • Boot to Internet Recovery Boot (hold altcmdR while booting). You will see a spinning globe while booting to a NetBoot image from Apple. Depending on your Internet connection this will take some time (~5 minutes on a 50 Mbit/s line)
  • Open Disk Utility and erase/repartition your internal disk
  • Quit Disk Utility and open "Reinstall OS X..." which will install the system your Mac was delivered with.
  • After installing the (old) system and configuring your Mac open App Store, enter your Apple ID credentials, download Sierra and upgrade the system.
  • Im not familiar with the file system on mac. But if I create a new partition (cause I dont want to loose my files) will I able to open the other drive like a flash drive and access my other files from there?
    – Niana
    Jul 17, 2017 at 19:13
  • Looking at the drives and sizes there doesnt seem to be anything on it. I was going to try booting with an external drive to see
    – Niana
    Jul 17, 2017 at 19:22
  • @Niana If you have a fully bootable drive (not just a bootable macOS installer drive!), boot to it, install TeamViewer, invite me to a TV session and I will have a closer look...
    – klanomath
    Jul 17, 2017 at 19:27
  • im going to make a fully bootable drive now.
    – Niana
    Jul 17, 2017 at 19:30
  • @Niana This requires to install macOS/OS X to an external drive and configure system/network etc. and one admin user! Don't install macOS to your internal SSD drive by accident! You won't be able to recover anything/much!
    – klanomath
    Jul 17, 2017 at 19:33

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .