OS X Error – An error occurred while preparing the install

Trying to reinstall OS X, getting an error message “An error occurred while preparing the installation

When trying to reinstall OS X, getting the error message “An error occurred while preparing the installation. Try running this application again”. This prevents you from completing the installation of your macOS software. Today’s post will go over the steps you need to correct the OS X Error.

Sometimes the most difficult issues have the simplest solutions. My current situation with a MacBook Pro just happens to be one of those situations. In this case, I was handed the MacBook Pro by a client because it would not completely boot up, not even after trying all of the keyboard boot-up functions (like holding the shift key on bootup). So the decision was made to reinstall the macOS (which was installed on it), using the Mac Disk Utility.  Simple enough, except for the fact that every time I tried to do the reinstall, I kept getting the error and the reinstall would not complete.  The following steps are what I discovered in order to fix the error so that the reinstall can complete.

This Issue You Are Seeing

• Log In to the Mac Disk Utility screen by holding down “Command Key” + R during boot.  Once you get into the OS X Utilities you select “Reinstall OS X” and hit continue

• When you start the reinstall you will get a message about verifying eligibility with Apple. Hit continue

• If you are going to get the error, this is the point where it will come up. Unfortunately, Apple gives you a seriously vague message “An error occurred while preparing the installation”. That message does NOT explain what went wrong.

Fixing The Reinstall Error

• From this point, click on Utilities –> Terminal

• When the terminal window opens, type date and hit enter. What you will notice is that the date listed will be wrong.  That wrong date is what is causing the reinstall error.

• To correct the wrong date –>  type date followed by MMDDHHMMYYYY  (Month – Date – Hour – Minute – Year)

• At this point just exit the Terminal box and try to run the reinstall again

These steps should now correct your install issue with OS X.

Final Thought 

As said at the start of this post, sometimes the most difficult issues have the simplest solutions. Hopefully, this simple solution helps.