Got a tip for us?Let us know

a. Send us an email
b. Anonymous form

Boot Camp Won’t Work With macOS Mojave on 2012 27-Inch iMac With 3TB Hard Drive

Monday September 24, 2018 1:56 PM PDT by Juli Clover

Apple today shared a support document that will be of interest to customers who own a late 2012 27-inch iMac with a 3TB hard drive and are attempting to upgrade to the macOS Mojave update.

There is an issue on this iMac model that results in the following alert when attempting to install macOS Mojave: "Installation cannot proceed with Boot Camp configured."

imac 2013 color
To fix this problem, Apple says that customers with the 2012 27-inch iMac with 3TB hard drive will need to completely remove the Boot Camp partition using Boot Camp Assistant before macOS Mojave can be installed.

After upgrading to macOS Mojave, Boot Camp will not be able to be used to install Windows on these machines. No other iMac models appear to be affected by this issue.

Related Forum: macOS Mojave

Top Rated Comments

macduke

96 months ago

Good thing Apple designs their own hardware. The software only has to run on a limited subset of hardware so it's easier for them to test and focus on making a good user experience. /s

Score: 25 Votes (Like | Disagree)

Val-kyrie

96 months ago

What???

How does this make any sense? Is Apple really listing the 2012 iMac as supporting Mojave then?

This seems like a serious oversight.

Score: 8 Votes (Like | Disagree)

techguy9

96 months ago

That’s oddly specific. Hopefully it can be resolved soon.

Score: 8 Votes (Like | Disagree)

neek

96 months ago

Not the only model affected. I have a 2013 iMac with Bootcamp on a Fusion drive and Mojave happily installed... it just broke my Bootcamp in the process.

https://forums.macrumors.com/threads/mojave-breaks-bootcamp-on-fusion-drive.2142473/
[doublepost=1537822253][/doublepost]

I seem to remember that BIOS emulation on EFI tends to not support drives over 2TB. Maybe that's the root cause? In that case, I wouldn't expect it to get resolved.

It's odd that Boot Camp would still be using BIOS emulation, I'm sure Windows 10 prefers EFI.

Boot Camp on 3 TB Fusion drives had to do a lot of voodoo. The start of the Windows partition had to be within the first 2 TB of the disk. High Sierra did some Core Storage tricks and put the Windows volume in the middle and had HFS+ partitions around it.

This is how my partition looked (when it worked):

Score: 6 Votes (Like | Disagree)

Shoju

96 months ago

No other iMac models appear to be affected by this issue.

I wish. I ran into the same message trying to install Mojave on my late 2014 iMac (27", Retina 5K, 3TB Fusion Drive). What's going on?! Don't tell me I won't be able to use Boot Camp again after updating to Mojave!?

Score: 4 Votes (Like | Disagree)

computersteve

96 months ago

Now if I owned this model i'd be pissed... I love bootcamp.

Score: 4 Votes (Like | Disagree)

Read All Comments

Popular Stories

iOS 26.3 and iOS 26.4 Will Add These New Features to Your iPhone

Tuesday February 3, 2026 7:47 am PST by Joe Rossignol

We are still waiting for the iOS 26.3 Release Candidate to come out, so the first iOS 26.4 beta is likely still at least a week or two away. Following beta testing, iOS 26.4 will likely be released to the general public in March or April. Below, we have recapped known or rumored iOS 26.3 and iOS 26.4 features so far. iOS 26.3 iPhone to Android Transfer Tool iOS 26.3 makes it easier...

• 30 comments

Apple's CarPlay Ultra to Expand to These Vehicle Brands Later This Year

Sunday February 1, 2026 10:08 am PST by Joe Rossignol

Last year, Apple launched CarPlay Ultra, the long-awaited next-generation version of its CarPlay software system for vehicles. Nearly nine months later, CarPlay Ultra is still limited to Aston Martin's latest luxury vehicles, but that should change fairly soon. In May 2025, Apple said many other vehicle brands planned to offer CarPlay Ultra, including Hyundai, Kia, and Genesis. In his Powe...

• 90 comments

Apple's Next Launch is 'Imminent'

Sunday February 1, 2026 12:31 pm PST by Joe Rossignol

The calendar has turned to February, and a new report indicates that Apple's next product launch is "imminent," in the form of new MacBook Pro models. "All signs point to an imminent launch of next-generation MacBook Pros that retain the current form factor but deliver faster chips," Bloomberg's Mark Gurman said on Sunday. "I'm told the new models — code-named J714 and J716 — are slated...

New MacBook Pros Reportedly Launching Alongside macOS 26.3

Sunday February 1, 2026 5:42 am PST by Joe Rossignol

Apple is planning to launch new MacBook Pro models with M5 Pro and M5 Max chips alongside macOS 26.3, according to Bloomberg's Mark Gurman. "Apple's faster MacBook Pros are planned for the macOS 26.3 release cycle," wrote Gurman, in his Power On newsletter today. "I'm told the new models — code-named J714 and J716 — are slated for the macOS 26.3 software cycle, which runs from...

• 141 comments

Apple Gives Final Warning to Home App Users

Tuesday February 3, 2026 8:55 am PST by Joe Rossignol

In 2022, Apple introduced a new Apple Home architecture that is "more reliable and efficient," and the deadline to upgrade and avoid issues is fast approaching. In an email this week, Apple gave customers a final reminder to upgrade their Home app by February 10, 2026. Apple says users who do not upgrade may experience issues with accessories and automations, or lose access to their smart...

• 65 comments