Before you erased your mac, you should have downloaded a copy of OS X Yosemite or whatever OS you wanted
Once this is complete I went to disk utilities and first re-erased the Mac SSD and then performed the OS X re-install from the recovery partition. It will not ask for any sign in with your apple ID. It will simply install the original OS X that came with your machine. Www.nerdsarmy.com'This copy of the Install OS X Mavericks application can't be verified. It may have been corrupted or tampered with during downloading.' I've been doing a clean up of a mac I was given. I followed the instructions to erase the disc through Mac OS X Utilities. I've gotten as far as reinstall Mac OS X. I am prompted to input my Apple ID and then get the message - This item is temporarily unavailable. Try again later. I held down COMMAND + R, went to Disk Utilities and unmounted then erased the harddrive. Then I went to reinstall mac os. It was on El Capitan. It asks me to connect to WiFi, I do. Then after a few clicks it asks to login Apple ID. After I try to do that, it says This Item is Temporarily Unavailable. Please try later.
to reinstall and made a bootable USB flash drive installer to avoid having to use the ever more unreliable
Apple Recovery Servers.
The certificates for several of Apples OS's expired in October 2019, Apple haven’t bothered getting these updated on
their Recovery Servers with valid certificates.
This may be the problem you are experiencing.
Try this workaround, we are going to set the time and date on your mac to a date previous to the expiry date of the certificates.
Connect your mac to your router via cable, not WiFi
Boot to your Recovery HD, click on Utilities in the menubar select Terminal.
Make sure WiFi is switched off, it can reset the date back to today.
Enter a new date, for example or just copy and paste
sudo date -u 011421002017
enter your password
If Terminal returns an error saying sudo : command not found, then try again without sudo.
date -u 011421002017
You won't be prompted for a Password if you did not need to use sudo
Once the date has changed you can quit Terminal.
Now try downloading the OS.
Click on Install OS X, press Continue.
If this works then when the OS is installed and booted up you can Open System Preferences> Date & Time
and reset the time back to today.
After getting OS X Yosemite reinstalled on your mac you can now download a copy of Yosemite and make a
bootable USB flash drive installer, so you never have to go through this turgid experience again.
Click on the link below,
Go to Download macOS and click on OS X Yosemite 10.10
this downloads InstallMacOSX.dmg to your Downloads folder.
The next section can only be done on a mac that is capable of running Yosemite,
a mac that came preinstalled with an OS later than Yosemite will refuse to do the next bit.
When downloaded open to InstallMacOSX.pkg, double-click on
that and an installation window will open, this does not install Yosemite
but converts the InstallMacOSX.pkg to the Install OS X Yosemite.app which
you will find in your Applications folder.
(If the installation window asks which disk you want to install to, you must pick
the disk that you are booted to at the time. Not any internal or external disk that
you want to eventually install Yosemite on, that is for later.)
Create a bootable USB installer disk using the Install OS X Yosemite.app
in the Applications folder and the createinstallmedia command in the Terminal app.
Read the instructions here, (the link below also includes links to download other OS's
you may want to or are able to install)
Sep 17, 2021 12:12 PM