Tech Tip: ‘An Error Occurred While Preparing the Installation’ Fix
Having worked in Technical Support here at OWC for some time now, I have helped customers handle many different types of errors and problems that they have come across. Some such as, “The disk you inserted is not readable by this computer,” might have simple solutions like formatting the disk, and some are more difficult such as “My Mac keeps freezing. Help!”
Related: My Upgrades tool helps you get the most from your Mac
One error that customers often come across while upgrading their machines occurs during the re-installation of macOS or OS X, and it has a relatively simple fix.
Once booted into the recovery partition and after selecting “Reinstall OS X”, the “Eligibility Verification” window shows up. The error occurs as soon as you click “continue”. An unspecified error shows up which states “An Error occurred while preparing the installation. Try running this application again.” Upon doing so, the same exact error pops up. Nothing has been done to have this occur, so what exactly is going on?
While this can be frustrating, something quite simple is going on in the background that needs to be addressed. One of the checks that occur during “Eligibility Verification” is to see what time the machine thinks it is. If the computer is reporting the wrong time, an error will occur.
While there is a simple fix, it does require using the Terminal to accomplish. Many users might be wary of the Terminal, feeling like something could break and that it’s something only hackers and System Administrators use. While this can be true, the Terminal can be your friend and help you to resolve quite a long list of issues that commonly occur. But with great power comes great responsibility. Terminal can be destructive if its abilities are improperly used. My recommendation for those that are wary of this wonderful tool is to copy/paste commands or to type them very carefully and to double-check what was typed before execution.
To fix the aforementioned “unspecified error”, follow the steps below:
- First, click “OK” on the error window.
- Then click on “Utilities”, then “Terminal”.
- Once opened type in “date” without the quotes and hit enter. This will give you the computer’s current time and date.
- To fix the date, type in the current date/time in the following format: “date mmddHHMMyyyy”. (mm = two-digit month, dd = two-digit day, HH = 24 hour, MM = minute, yyyy = 4 digit year) So if it is currently 10:46am, June 19, 2015, the command would look like: “date 061910462015”.
- Once you have the current date/time inserted, you will then hit enter. You can double-check to see if it was set properly by using the “date” command once more, it should show the date/time you have just typed in (see image below).
- Once the proper date and time are set on the computer. Exit the Terminal and run the OS X installer once more. This time it should go through without any errors! If it doesn’t, feel free to contact an OWC technician for further assistance.
Looking to Downgrade from one OS to another? We have you covered!
- Downgrade from macOS 10.15 Catalina
- Downgrade from macOS 10.14 Mojave
- Downgrade from macOS 10.13 High Sierra
- Downgrade from OS X 10.10 Yosemite to OS X 10.6 Snow Leopard
More tech tips from OWC
Look for many more tech tips on macOS Yosemite, El Capitan, Sierra, High Sierra, Mojave and Catalina for your Mac or iDevice at the Rocket Yard!
Thank you so much
You Sir, are a hero!!! Thank you so much!!!!
WOW this worked! I have been trying to fix this for a year now and gave up decided to investigate and try one more time and it worked!!
I jinxed it, it asks for my apple ID and password and its saying “this item is temporarily unavailable”
Having similar issue but firmware time is correct? Trying to reinstall osx and getting same message? Any ideas?
Sensational. Worked exactly as you said it would. Thank you very much, I learned something tonight. Would be interesting to know why an incorrect date prevents the installation.
I faced this problem when installing El Capitan,10.11.6 from a local bootable usb to internal OWC SSD (yes,i put the SSD in first). I tried changing the date as in this article, and resetting with option + command + R + P and nothing helped.
Wow it worked. Its people like you that make having a Mac not a super huge headache.
thiis cool
hello
i am format my laptop and i click to restore but show me error
Thank you so much! i tried everything and even contacted apple and i could not find the answer for months! thank you so much!!!
I have followed the directions but it’s still saying command is not found. Also terminal- bash – 80×24 at the top and -bash-3.2# in the box
same!!!
I figured it out! It’s because you need a space between the word “date” and the numbers. I had typed them all together and kept getting the same message. Hope this helps!
Mine is showing the same thing. Bash- 80×40 at the top and -bash-3.2# in the box..
Thanks!
Thank You, Thank You, Thank You! I Cannot Thank you Enough! My laptop has been stuck at that restart screen for about 4 years now and I was finally able to turn it back on after changeing the date through the terminal! Thank you!
I have tried this and it starts to go through however once it asks me to log into the apple store i receive another error not allowing me to log in. any advice?
Dude, Thank you so so so much! I was on an hour call with Apple care and they couldn’t figure it out.
Thank you!
hi everyone
changing the date did not resolved it. any other suggestions
a surprising thing happen while trying everything to solve my installation problems. I created a bootable disk to install sierra because changing the date did not work. After using the bootable disk, an error again occurred “an error occurred while preparing the installation…” Just as I was about to give up, I again saw instructions to reset NVRAM. I did not try it thinking that its another solution that will lead me nowhere but lo and behold, after resetting it and without inserting the bootable disk the high sierra was installed.
Hi thank you :) But when i come to install OS X El Capitan, and when i have to agree so i cant use the disk to instill it on, bc the disk dittent show up on my pc? What is the problem? Hope you can help :) Tanks!
Lifesaver! Thank you! Bless you!
THANK YOU SO MUCH!!!So helpful !!!
Thank you!!!!!
thank you so much
That was unbelievably helpful! Thank you o much!!
This worked for my 2009 MacBook Pro, so strange how just changing the date and time affected installation
Thank you so much bro almost sold my laptop very informative kudos Time was set to 2001 lol wouldn’t connect to App Store this worked
I’ve spent days looking for a solution to this problem. THANK YOU!
A great help – thank you very much
Worked perfectly but after I agreed to terms of software license agreement and selected the main disk I sign in to the app store then it tells me “this item is unavailable” where do I go from there?
Followed your instructions perfectly but the installation won’t proceesame message is displayed again”Mac os x can’t be installed on this computer”
please is there any other solution to this.
Thanks. It helped
I get permission denied. I am an administrator level
date: bind: Permission denied
date: settimeofday (timeval): Operation not permitted
me too but my date is accurate and fine
THANK YOU!!! You’re a lifesaver!!!
Genius! Thank you!!
I would like to thank you sooooo much
You’re an expert
This article is the most useful article I have ever seen
Hi, After entering the date time etc it comes up with command not found, is this because I’m entering the information wrong?
U need to type date in the same line then the correct time
Date 0101010101
I have one more question: how do I change TZ. The date command shows PST, but I’m on a diferent Time Zone. Thanks!
hey thank you it worked for me but i couldnt get to install because it said the disk is locked how can i unlock it? reason im trying to reinstall is because my computer wont boot fully
Felt like a total hacker. It fixed my problem, thanks !
thank you
Set the current date and time – reset/remove the current MAC O/S on HD.
have another IOS device to received the pin
initiate a new download
pin will arrive on new IOS device (like iPAD)
adding the pin to the end of your password
4 hours later you will have a new MAC O/S
PS you r
will need a valid AppleID user and password
Huge. This fixed my problem. Thanks!
Thank you so much, this worked perfectly!
Mine is still giving me this error, it comes up after i have agreed to terms and conditions just as the system is about to restart. I have OS X Mavericks, trying to install macOs High Sierra, I have other updates that are still pending though…I need help, so many applications need the software to be updated before they will work.
I’ve done that but still comes up with the same thing
Thank you, this was what I needed. This article was very helpful.
I was trying to update a Virtual Machine with Lion, and this solved it for me. I just had to change in the System Preferences. Thanks for sharing!
I was trying to update a Virtual Machine with Lion, and this solved it for me. I just had to change in the System Preferences. Thanks for sharing!
Wow that worked very well. Thumbs up
I went to the terminal and entered the date and time as directed. I then tried to install macOS Sierra. It worked fine until the 20 second mark. Then I get the following message: “An error occurred while preparing the installation. Try running this application again.” Multiple runs give me the same result. Do you have any ideas as to what else I can do to make this work?
hi marelen did you get an answer?
I’m having the same problem. Additional advice would be great.
I have this same exact issue
Same here.
I have read on other threads that trying after 3 to 4 times of download it starts working fine.
So I’m just deleting installer and trying to download again. (MacOS Mojave)
How do I do this can anyone help me out
OMG!! .. This is just what i was looking for.. Thanks so much.. It Worked!!
I use High Sierra and i cannot see the utilites tab above..?? What to do please help urgent