Bootcamp not booting in Big Sur using Macbook Pro Late 2014

gianfranco09 wrote:

Hoping for a miracle this season...

Take a look at

• Boot process of Mac computers - Apple Support
• Boot process of Mac computers without an Apple T2 Security Chip - Apple Support
• https://eclecticlight.co/2020/09/16/boot-volume-layout/

The role of boot.efi is documented. Till Apple can work out the gremlins in Big Sur UEFI, my recommendation is to stay on Catalina.

I am having the same Windows 10 boot-up problem on my mid-2014 15" MacBook Pro after upgrading to mac OS Big Sur. I really do not want to have to reinstall Windows 10 using bootcamp and have not had any issues with bootcamp on past versions of mac OS including latest version of Catalina. I granted full disk access to System Preferences, but computer still won't boot into Windows. When I open my bootcamp hard drive icon on my desktop I can see all of my Windows files and folders. When I go into Disk Utility and select my Bootcamp partition the First Aid option is greyed out. I am fairly computer literate but don't want to risk doing something that accidentally deletes my Windows 10 partition and data. It would be extremely helpful and greatly appreciated to have a detailed, step-by-step procedure on how to fix this issue without having to reinstall Windows 10. Thanks in advance for your help.

Just share here with you that I had a phonecall from Applecare and they asked questions about this issue.

He asked when installed Big Sur and asked me to restart and tell what happens.

And it booted again in Apple and not windows, although it was set as startingdisk in Apple (and windows).

They had me run and I uploaded the results of the systemdiagnose.

He said Appleteam bootcamp will for sure investigate this and it will be resolved in an update.

Hope this will speedup the resolvent if this issue.

z3thon wrote:

https://discussions.apple.com/content/attachment/53c93bb7-c794-4312-8811-9f972ee35edb

https://discussions.apple.com/content/attachment/ff3c20d3-3760-4b6f-b801-d57f66a24812

Please start a new discussion. Your 2019 Mac is not the same as OP (2014 Mac).

I have a MacBook Pro 2014 15 inch. I had a similar problem with Big Sur. I had not installed Windows on it.

• I put System Preferences in the Full Disk Access list.
• I ran through the Book Camp Assistant
• The Mac refused to boot into Windows, so I restarted and held down the option key so it showed available disks to boot from.
• 3 disks appeared on the boot screen. Choosing "Windows' doesn't do anything, you have to choose "EFI Boot". This will boot from the USB key.
• Move on with installing windows.

Which macOS version did you upgrade from?

• Does System Preferences have full-disk access to the Bootcamp partition?
• Check if you have a Microsoft directory in the EFI(ESP) partition.

Also, the APFS layer has changed in macOS, which may cause issues AppleControlPanel.exe. As a test, if you have Catalina or Mojave on an external disk

This worked for me but it’s still glitchy to load windows .

1. open terminal
2. Type “diskutil list”

find your windows disk name (for example it may read disk0s2)

3. type in terminal “sudo diskutil mount disk0s2” “sudo diskutil unmount disk0s2”

4.Restart your computer and hold down option.

5.after you put click into boot camp continue to hold down options

6.If it restarts into Mac OS just restart and boot windows and continue to hold down options until windows boots up

Note: windows might try to load up a repair mode but it should let you also load up windows . This will be a slow load up time but after 2 restarts it worked for me. Good luck . Apple will have to provide an update for this bug .

I have found a solution for the exact same issue, thanks to one of Apple's senior tech support agents!

Please do the following steps:

1. Go to "System Preferences"
2. Select "Startup Disk"
3. Choose the "Windows" drive
4. Reboot for a couple of times until you can log back into Windows

I have followed those exact steps and it worked for me. So I hope it works for everyone too!

This worked for me:

Boot windows as described above (option key ...).

Once windows is running, goto Boot Camp in Taskbar System Tray. Use Control Panel to select windows as your boot drive and you're done.

MAK787 wrote:

Probably they have listened to the complaints of update bricking some Mac models, specially the 2013 & 2014 ones.

I can still download macOS Big Sur on a 2012 MBP running Sierra. This was a few minutes ago.

I am surprised that the update is missing from your Software Update. Can you check if you can access the App Store and see Big Sur?

I am actually happy to see this. If they have stopped problematic models from updating, its actually good. Instead of bricking one's mac, its better to wait for more stable release. Yes, I can access app store and by searching, it shows it right there but it doesn't show in system preferences --> software update.

everything is showing up properly once I’m booted into MacOS. All of my issues happen during the boot.

no luck with multiple restarts like others here. Restarted 4 times with Win10 as the default. No luck.

I have the same issue on my mid 2014 Macbook. Default setting is changed to bootcamp but need to restart and interrupt (option button) and select again Windows/bootcamp. Sometimes even two attemps neccesary. And the startup takes a lot of time, before it was quick. Not know how to resolve!?

kuda00 wrote:

I managed to get mine working by follow instructions from this video https://www.youtube.com/watch?v=JdQ-MY0Myww Good luck.

You can do the same using

sudo diskutil mount disk0s1

sudo diskutil unmount disk0s1

System Preferences needs Full Disk Access to be able to switch to Bootcamp.