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Problems installing Big Sur

I have been trying to install Big Sur it keeps getting stuck. When I reboot it takes me back to the apple logo screen and loading bar at 25 mins to go. Then it counts down to ‘less than one minute’ and gets stuck there. All I did was try and upgrade to Big Sur.


I spoke to apple support and they couldn’t help and said I would have take it to an apple store for review. There was nothing wrong with my Mac when running the diagnostics.


I can’t believe that trying to download the latest update could be so catastrophic??


can anyone help please?

MacBook Pro 13″, macOS 10.15

Posted on Feb 12, 2021 2:52 PM

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Posted on Feb 16, 2021 3:03 AM

Many thanks for this. I managed to reload Catalina without too many problems. I think I might avoid Big Sur for now. I did have an issue with FileVault temporarily but managed to resolve it. Good news is that the laptop is now working again and I do not need to go to an Apple Store for an appointment. Thanks again for your help.

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Question marked as Top-ranking reply

Feb 16, 2021 3:03 AM in response to HWTech

Many thanks for this. I managed to reload Catalina without too many problems. I think I might avoid Big Sur for now. I did have an issue with FileVault temporarily but managed to resolve it. Good news is that the laptop is now working again and I do not need to go to an Apple Store for an appointment. Thanks again for your help.

Feb 13, 2021 2:03 PM in response to PaddyJo1

You can try to examine the Big Sur install log located on the "Update" volume on the internal drive for clues to the failure to complete the install. You will either need to boot from an external macOS drive, or access the log from Recovery Mode using the Terminal command line, or you can put this Mac into Target Disk Mode to attach it to another Mac so you can access the installer log. Maybe you can figure out what stopped the installer and fix the issue. If you can access the Big Sur installer log, then post the last 50 lines here using the "Additional Text" icon which looks like a piece of paper.


You can also restore macOS from a backup made before you attempted to upgrade macOS.


There is a chance you can revert to the "local" APFS snapshot that the Big Sur installer as it began the upgrade process. To do this you need to boot into Recovery Mode and select the "Restore from Time Machine Backup" even if you don't use Time Machine. Select the "local" option and select a snapshot dated from just before you ran the Big Sur installer. After the system reboots you should have the system back to how it was before the attempted upgrade.


Always have frequent & regular backups. You should always make sure to have a good backup before doing any major system changes such as upgrading macOS.

Feb 14, 2021 4:05 PM in response to PaddyJo1

I've heard some reports that some systems need to upgrade to macOS 10.11 El Capitan before being able to upgrade to later versions of macOS. macOS 10.13 High Sierra was another possible pivotal OS as well.


Keep in mind many of the third party apps you have installed with Yosemite won't be compatible with macOS 10.15+ without updates to the software. Beginning with macOS 10.15 Catalina 32 bit apps are no longer supported so you should either upgrade any third party 32 bit apps to 64 bit versions or uninstall them before upgrading to macOS 10.15+.

https://support.apple.com/en-us/HT208436


It may actually be better to just perform a clean install of macOS 11.2 Big Sur and migrate just your user account(s) so you can manually download 64 bit versions of your third party apps and install them. This would probably be best so that you end up with a nice clean system to start with again.

https://support.apple.com/guide/disk-utility/erase-and-reformat-a-storage-device-dskutl14079/mac

Problems installing Big Sur

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