26.4 beta and RC versions are unable to be created on anything but 26.4 beta host OS

Question

Created 2d

Replies 4

Boosts 2

Participants 4

We're trying to create 26.4 beta and RC VMs on 15.x and 26.3 host OS' without success. We see

Tue Mar 17 17:27:36 40 anka.log (install) 45803: failed to install macOS: Error Domain=VZErrorDomain Code=10006 "Installation requires a software update." UserInfo={NSLocalizedFailure=A software update is required to complete the installation., NSLocalizedFailureReason=Installation requires a software update.}

Yet, if we create it the same way on 26.4 beta host OS, it works.

We've tried the usual tricks of installing latest Xcode and preparing it (accepting license, etc). But, they don't work on 26.3 and 15.x.

What's the trick to get the creation of 26.4 to work on <= 26.3 host OS?

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Answer 1

DTS Engineer OP

Apple

1d

AFAIK there’s no magic here. And I tried reproducing this on my main work Mac and didn’t have a problem. Specifically:

On macOS 26.3.1, I downloaded the current 26.4rc seed (UniversalMac_26.4_25E243_Restore.ipsw).
Using an off-the-shelf Virtualization framework app [1], I created a VM from that.
It installed and booted, and I was able to run all the way through MacBuddy and get to the Finder.

I’m not sure why this is failing in your environment.

This Mac is production hardware that’s only ever run released system software (plus various Xcode beta seeds).

When I wrote the above I hadn’t yet installed Xcode 26.4rc. So I installed that and repeated the test. It didn’t change anything. Things continued to work.

Share and Enjoy
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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

[1] VirtualBuddy 2.1.

0

Answer 2

norsegaud OP

1d

This is what I see on a brand new M5 with 26 Mobile Device Support installed + using Virtualbuddy.

Screenshot 2026-03-20 at 7.13.43 AM.png

I'm not entirely sure why your environment works actually.

1

Answer 3

kthchew OP

21h

I'm also encountering this trying to make a 26.4 RC VM on a macOS 15.7.4 (24G517) host (a M3 MBP) (FB22286320).

I have a VM working from a previous 26.4 beta that was originally on an earlier version of 26, but I wasn't able to upgrade it to the RC via Software Update due to storage constraints :( maybe it would work to make a VM with an earlier macOS version then update it? I haven't found time to test whether that works, though.

1

Answer 4

kthchew OP

9h

AFAIK there’s no magic here. And I tried reproducing this on my main work Mac and didn’t have a problem.

@DTS Engineer When I have this issue, it also comes with a prompt that appears offering to download the device support files, but this fails because the files aren't available from the software update server. Given that you're an Apple employee, is it possible that your work Mac has access to an internal software update server that offers the required device support files, but that the public software update server doesn't?

1