Big Sur Locked in Endless Reboot Cycle

Question

Big Sur Locked in Endless Reboot Cycle

Hello,

I've successfully downloaded Big Sur but when I run the updater, my iMac (late 2017) reboots, shows a white progress bar that gets to about 20%, then the machine reboots again ... and then the whole thing repeats. After two hours of this (and about 20 reboots), I gave up, booted into Recovery Mode, and resintalled Catalina.

Any thoughts/suggestions? Big Sur installed fine on my older MacBook Air but the iMac is very unhappy.

Is it, for example, possible to install Big Sur from Safe Mode?

Many thanks.

iMac Line (2012 and Later)

Posted on Nov 13, 2020 02:36 AM

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Answer 1

raina_b22

Community Specialist

Nov 19, 2020 12:12 PM in response to Andy Bannister

Greetings Andy,

It sounds like you are unable to instal Big Sur on one of your Mac computer. We know how important having the latest macOS is for you. You’re in the right place to find a resolution.

Here's a resource that can help on how to upgrade to Big Sur:

• How to upgrade to macOS Big Sur.

If you need continued assistance, then please reach out to our AppleCare phone support team via this link: Get Support.

Cheers!

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Answer 2

Nov 20, 2020 12:55 AM in response to raina_b22

Thanks — did all that and more! Apple Support have now picked this up and it's been escalated up the chain, as it looks like I (and others reporting the same issue) have found a nasty bug in the installer process. I had an hour on the phone with a Senior Adviser two days ago and now they have engineering pouring over log files I've sent them ...

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Answer 3

Nov 20, 2020 02:39 AM in response to Andy Bannister

(And apparently I can't change the computer I picked that's listed at the bottom of my initial question ... Ah well, never mind. Anyway, it's a 2017 iMac and the Apple engineers are helpfully on the case ...)

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Answer 4

Owl-53

Level 10

100,249 points

Nov 20, 2020 02:36 AM in response to Andy Bannister

Andy,

Your profile listed, is showing iMac late 2012. If this is correct, sorry to report, it does not qualify for the Big Sur Upgrade. Check over Here to see where the cut-off happens.

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Answer 5

Nov 20, 2020 02:37 AM in response to Owl-53

Hi, thanks for catching that, I need to update my profile :-) It's a 2017 iMac with the problem.

Off to update my profile ...

Andy

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Big Sur Locked in Endless Reboot Cycle

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