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 Avatar
macduke
92 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 Avatar
Val-kyrie
92 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 Avatar
techguy9
92 months ago
That’s oddly specific. Hopefully it can be resolved soon.
Score: 8 Votes (Like | Disagree)
neek Avatar
neek
92 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):

Attachment Image
Score: 6 Votes (Like | Disagree)
Shoju Avatar
Shoju
92 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!?

Attachment Image
Score: 4 Votes (Like | Disagree)
computersteve Avatar
computersteve
92 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 Battery Glass Feature

iPhone 16 Pro Max 80% Charge Limit: One Year Later, Was It Worth It?

Wednesday September 24, 2025 3:58 pm PDT by
With the iPhone 15 series, I did an experiment and kept my iPhone's Charge Limit set at 80 percent for an entire year. It provided an interesting look at the impact of charge limits on battery longevity, so I decided to repeat it for the iPhone 16 line. Since September 2024, my iPhone 16 Pro Max has been limited to an 80 percent charge, with no cheating. As of today, my battery's maximum...
Read Full Article • 569 comments
Home Hub Command Center with Dome Base Feature

Apple Working on All-New Operating System

Thursday September 25, 2025 1:11 pm PDT by
Apple is developing an all-new operating system codenamed "Charismatic," according to Bloomberg's Mark Gurman. Apple smart home hub concept based on rumors This is likely Apple's long-rumored "homeOS" operating system. In a report last month, Gurman said both Apple's rumored smart home hub in 2026 and tabletop robot in 2027 will run the new operating system. He said the software platform ...
Read Full Article
AirPods Pro 3 Newsroom

Apple's 'Back to School' Offer Ends Soon, Now Applies to AirPods Pro 3

Wednesday September 24, 2025 7:20 am PDT by
Apple's annual "Back to School" promotion for students ends soon, so act fast if you want to score free AirPods with the purchase of an eligible new Mac or iPad. Until Tuesday, September 30, college students and qualifying educational staff in the U.S. can receive free AirPods 4 with Active Noise Cancellation when they purchase an eligible new Mac or iPad from Apple. This is a $179 value. ...
Read Full Article • 17 comments
iOS 26

iOS 26.0.1 Update for iPhones Coming Soon — Here's What to Expect

Thursday September 25, 2025 12:40 pm PDT by
Apple is preparing to release iOS 26.0.1, according to a private account on X with a proven track record of sharing information about future iOS versions. MacRumors has also seen evidence of iOS 26.0.1 in its visitor logs in recent days. It is likely that iOS 26.0.1 will fix a camera-related bug on the new iPhone Air and iPhone 17 Pro models. In his iPhone Air review, CNN Underscored's...
Read Full Article
iPhone 17 Pro Colors

Skipped the iPhone 17 Pro? Here's What is Rumored for iPhone 18 Pro

Tuesday September 23, 2025 8:55 am PDT by
While the iPhone 18 Pro and iPhone 18 Pro Max are still a year away, there are already a few rumors about the devices that offer an early look ahead. Below, we have recapped some of the early iPhone 18 Pro rumors so far. This story was published previously, and it has been updated to reflect the latest rumors. Many early rumors prove to be true, but nothing is confirmed yet, and Apple's...
Read Full Article • 106 comments
iOS 26

Everything New in iOS 26.1 Beta 1

Monday September 22, 2025 12:44 pm PDT by
Apple released the first beta of iOS 26.1 today, just a week after launching iOS 26. iOS 26.1 mainly adds new languages to Apple Intelligence, but there are a few other features that are worth knowing about. New Apple Intelligence Languages Apple Intelligence is now available in Danish, Dutch, Norwegian, Portuguese (Portugal), Swedish, Turkish, Chinese (Traditional), and Vietnamese. AirPo...
Read Full Article • 143 comments
apple tv 4k new orange

Next Apple TV Expected to Launch This Year With These New Features

Monday September 22, 2025 10:00 am PDT by
The next Apple TV is expected to be released later this year, and a handful of new features and changes have been rumored for the device. Below, we recap what to expect from the next Apple TV, according to rumors. Likely Features N1 Chip With Wi-Fi 7 Last year, Bloomberg's Mark Gurman said the next Apple TV would be equipped with Apple's own combined Wi-Fi and Bluetooth chip, which is...
Read Full Article • 102 comments
Apple More Personal Siri Ad

Apple Responds to U.S. Class Action Lawsuit Over Delayed Siri Features

Friday September 26, 2025 6:57 am PDT by
In March, Apple delayed the launch of its personalized Siri features, and soon after the company was hit with multiple class action lawsuits over the situation. The plaintiffs said they never would have purchased an iPhone 16, or would have paid less, had they known Apple's marketing about the Siri features was false. In the U.S., all of the complaints were consolidated into one class...
Read Full Article • 159 comments