Bootcamp could not locate macOS boot volume

[bentom13]

I have a 2016 MBP with Windows 10 installed via Bootcamp.

When i start up it normally boots straight into macOS and if i want to go into windows i just hold down the option button when turning on. HOWEVER, i have turned it on this morning to find it boots straight into windows and holding the option key does nothing.

I have tried using bootcamp manager but this just comes up with the message "Bootcamp could not locate macOS boot volume."

I have looked on disk management on windows and the Bootcamp partition is still there, along with the macOS partition size - but not labelled macOS???

I have a bad feeling that it has erased my macOS partition if that is possible?

Anyone have any ideas? Trying to contact Apple Support but been waiting forever!

 

[Shirasaki]

You could try to enter recovery mode of your Mac. I don’t remember how to do it but you can search it online.
If under recovery mode, your Mac partition is still not there and you cannot repair it, something terrible has happened.

 

[bentom13]

You could try to enter recovery mode of your Mac. I don’t remember how to do it but you can search it online.
If under recovery mode, your Mac partition is still not there and you cannot repair it, something terrible has happened.

It did not respond to any commands when booting (Option key, Command-R etc.) So I was unable to reselect my macOS partition to boot into, or boot into recovery mode etc. It was like a windows laptop with no trace of mac. So i tried using window commands to get into the windows boot menu. I selected the Start up repair and it booted back into macOS!

I believe Windows cannot see the windows partition so there is still some issue moving between OS's but at least i know how to get back to macOS!

Will update as I find more incase others have the same issue.

 

[Shirasaki]

I selected the Start up repair and it booted back into macOS!

The dankest moment of this troubleshooting. No one would expect that!
This shows how fragile apple’s boot camp system is. Hence I use a dedicated PC for everything windows.

 

[bentom13]

The issue has been escalated to the engineering team - hopefully have a solution within 2-3 working days.

 

[Shivetya]

is this related to the new file system under OS X? ever since High Sierra the Bootcamp app in Windows10 cannot find the partition but holding the option key during boot I can manually select it

 

[bentom13]

is this related to the new file system under OS X? ever since High Sierra the Bootcamp app in Windows10 cannot find the partition but holding the option key during boot I can manually select it

No, this isn’t the problem.

The problem is that when I shutdown from windows and then turn it back on, it boots straight back into windows - which should not happend.

This wouldn’t be such an issue if holding down the option key worked, but it doesn’t in this scenario like it does on a normal boot.

Hope that makes sense?

 

[salman4uall04]

No, this isn’t the problem.

The problem is that when I shutdown from windows and then turn it back on, it boots straight back into windows - which should not happend.

This wouldn’t be such an issue if holding down the option key worked, but it doesn’t in this scenario like it does on a normal boot.

Hope that makes sense?

Hi,

Did your problem sorted out? I am having same problem and every time I switch on mac I have to press option key to go into mac. Please do let me know if you got a solution. Thanks.

 

[bentom13]

Hi,

Did your problem sorted out? I am having same problem and every time I switch on mac I have to press option key to go into mac. Please do let me know if you got a solution. Thanks.

In short no, however, the main problems seems to have gone. After shutting down in windows, I can restart in Mac OS rather than auto booting into Windows again. However, the touchbar does not seem to work so i have to restart Mac OS whenever returning to it from windows.

Although it sounds like you have a different problem to me as when I used to switch on the Mac after being in windows it was totally unresponsive to any Mac commands, but would respond to windws commands when booting.

Hope that makes sense.

 

[Mcmeowmers]

In short no, however, the main problems seems to have gone. After shutting down in windows, I can restart in Mac OS rather than auto booting into Windows again. However, the touchbar does not seem to work so i have to restart Mac OS whenever returning to it from windows.

Although it sounds like you have a different problem to me as when I used to switch on the Mac after being in windows it was totally unresponsive to any Mac commands, but would respond to windws commands when booting.

Hope that makes sense.

On macOS select macOS as your start up disk. Boot into windows and reopen boot camp control panel. Re select macOS as the boot up disk.
For some reason it doesn't obey the setting and you have to reselect it.

 

[Fastrip66]

It did not respond to any commands when booting (Option key, Command-R etc.) So I was unable to reselect my macOS partition to boot into, or boot into recovery mode etc. It was like a windows laptop with no trace of mac. So i tried using window commands to get into the windows boot menu. I selected the Start up repair and it booted back into macOS!

I believe Windows cannot see the windows partition so there is still some issue moving between OS's but at least i know how to get back to macOS!

Will update as I find more incase others have the same issue.

Zap pram. I had the same issue, after zapping pram 3 times my option to hold down the option key at bootup RIGHT AFTER the chime has worked since no issues for a year or more now.
[doublepost=1548199616][/doublepost]

Hi,

Did your problem sorted out? I am having same problem and every time I switch on mac I have to press option key to go into mac. Please do let me know if you got a solution. Thanks.

Select the Mac disk as the startup disk in mac system preferences so it boots to Mac by default. When You want windows reboot and immediately after the chime hold option key down and arrow to windows and hit enter.

 

[cwin]

It did not respond to any commands when booting (Option key, Command-R etc.) So I was unable to reselect my macOS partition to boot into, or boot into recovery mode etc. It was like a windows laptop with no trace of mac. So i tried using window commands to get into the windows boot menu. I selected the Start up repair and it booted back into macOS!

I believe Windows cannot see the windows partition so there is still some issue moving between OS's but at least i know how to get back to macOS!

Will update as I find more incase others have the same issue.

 

[MagnusVonMagnum]

I've had it not recognize Boot Camp in Mojave and I've had Windows not recognize Mojave. It "seems" like if macOS is selected in the mac startup pane Boot Camp recognizes macOS, but if Windows is selected it doesn't (I haven't tested this enough times to be sure that's the pattern) and I don't know why Windows hasn't appeared a few times in macOS, but I do know after turning trim control on I could not boot into macOS until I booted into a recovery disk, used repair and then used the "startup" program to select macOS (a manual "bless" didn't work; it couldn't boot when you selected it; it would just hang at the apple logo and no progress bar would appear, but after selecting it with the startup preference pan from recovery, I used verbose mode (CMD-V) to see where it was hanging up and it booted that very time and ever since (and trim is working fine with 500MB/sec write times once again on my 2012 Mac Mini Server).

So the idea that Boot Camp can't "see" APFS doesn't seem true (I've actually got MacDrive installed at the moment so Windows 10 Pro can "see" and at least read every Mac volume here including read/write to my HFS+ media drives) as it doesn't do it every time as above. But what's odd is it's been two flipping YEARS and Apple still hasn't fixed this bug.... Or maybe that's not odd at all for Apple these days.