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macrumors bot
Original poster
Apr 12, 2001

Shortly after the launch of Apple's new M1 Macs, we saw reports that attempts to restore and reinstall macOS on those machines right away could result in an installation error that would leave your Mac non-functional.


Specifically, the error message would read: "An error occurred preparing the update. Failed to personalize the software update. Please try again."

Over the weekend, Apple posted detailed instructions for users experiencing this issue. Specifically it seems the issue arises if you erase/restore your Mac before upgrading to macOS Big Sur 11.0.1.
If you erased your Mac with Apple M1 chip before updating to macOS Big Sur 11.0.1, you might be unable to reinstall macOS from macOS Recovery. A message might say “An error occurred while preparing the update. Failed to personalize the software update. Please try again.”

Use either of these solutions to reinstall macOS. You should then be able to use macOS Recovery as expected when reinstalling macOS in the future.
Apple suggests that you could create a bootable installer using another Mac. Otherwise, Apple details a more technical 17 step process using Terminal to restore your M1 Mac to a functional state.

If you are still having trouble, Apple recommends contacting support, and you can also visit our ongoing forum thread where users are troubleshooting this specific issue.

Article Link: Apple Provides Instructions to Fix macOS Reinstallation Errors on M1 Macs


macrumors 68000
Jul 6, 2012
1st generations of anything tend to have bugs, teething issues and things like this (if you do some searching you'll see there are issues going on with the new PS5's and Xbox Series S's and Series X's as well). Its disappointing to see and stressful for the poor folks dealing with them.


macrumors P6
Oct 23, 2010
It's important to note that these have been out for less than a week. Of course there will be issues that get ironed out, which is why it is a good recommendation for casual users to wait a few weeks while the early adopters identify and sort out the issues. Both the hardware AND OS are new.
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macrumors regular
Nov 16, 2008
My M1 MBP is on order. This is a speed bump for a few. Worth it compared to the PPC -> Intel transition. We have speed, battery life, and impressive performance.


macrumors P6
Oct 23, 2010
True, though I don't think we see a "copy these terminal commands" instruction from Apple very often.

View attachment 1677227
You are right about that, but I think Apple chat or phone support had me run a terminal command on an older MacBook Pro when we were trying to diagnose a problem.


macrumors regular
Mar 20, 2007
Houston, TX
I’ve heard of putting a machine trough its paces, but wow... that’s quick.

Edit: PS: humor/smart assery intended. I get that it should work.


macrumors 65816
Jan 10, 2018
You are right about that, but I think Apple chat or phone support had me run a terminal command on an older MacBook Pro when we were trying to diagnose a problem.
Same here....sometime ago when I first purchased my current MBPro (2017).


macrumors newbie
Aug 5, 2020
Since the terminal instructions actually rely on downloading an updated package from Apple, they could have simplified the procedure and just direct users to download and execute a script, which could also handle the volume name identification more graciously.


macrumors 68020
Oct 21, 2009
I have owned a ton of Macs, this new air is by far the best computer that I have ever owned. I might return it though and get a 16gb model just so I can future proof it a bit now that I know how great it is. Too bad the upgrade costs so much or I would have just ordered the 16gb from the start


macrumors 6502
Apr 5, 2014
What a mess this company has turned into
What mess?
There was a bug in 11.0. Apple issued 11.0.1 but some people received the machine and immediately did a restore for any of various reasons. Since the machines shipped after 11.0.1 they had the bug in 11.0.

The fix is fairly simple for anyone that would have encountered the bug, ie: generic home users are not in the habit of doing a complete system restore out of the box, power users do that.
Oct 27, 2020
Oof I’m okay with those instructions since I like terminal but I can only imagine someone who doesn’t have technical acumen freaking out doing those steps.
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