Unable to install macOS Sequoia update 15.4 on my MacBook Pro

Dreadful experience here:

Facing the same issue and it completely damaged my system .

I had the same message as OP posted, and at some point my laptop was able to restart , proceeded with the update but failed.

At this Point, I was unable to start the laptop anymore, I was stuck in a boot loop forever.

• I tried recovery mode to run some diagnose and fix but amongst all the options available Only Reinstall Sonoma was possible.
• My current Volume was marked as "unable to downgrade", so I had to create a new disk and install Sonoma there.
• For 24 hours, now I have been installing Sonoma, upgrading to Sequoia 15.3.2 and moving ALL my Data over ! Stressful and losing time unable to work !
• At this point , I have 2 systems running 15.3.2, only one is bootable though.
• The new OS is still proposing to update every once in a while but unable to upgrade to 15.4 .
• I WILL NOT risk to update it before Apple fix it for sure.

You won't believe what happened after `sudo softwareupdate --fetch-full-installer -a --launch-installer -R`

It downloaded Sonoma MacOS and surely rejected it to launch. I have no clue why Sonoma if I'm on macOS Sequoia (MacBook Pro M3Pro)

This is precisely the problem I'm having. Earlier this year an iOS update did the same thing to my iPhone; stuck in the infinite reboot loop with no option but to wipe the system. Over 30 years using Apple products, I can't recall ever having this kind of catastrophic failure, let alone twice in six months. Sure, there were bad updates that got next-day patches, but a "you need to wipe your entire hard drive and start all over again" kind of failures just never happened.

Now I have to spend my weekend resetting and reinstalling and re-setting up the system.

This is a MacBook Pro 14" M3.

The upgrade was suggested by the system itself in Settings; I was just using the normal upgrade mechanism.

macOS 15.3.2 -> 15.4 was attempted.

Try booting into Safe Mode according to How to use safe mode on your Mac and and installing from there. I've had some problems installing updates in the past and booting into safe mode did the trick for me. I must have had some 3rd party software that was interfering with the installation.

NOTE 1: Safe Mode boot can take up to 3 - 5 minutes as it's doing the following; 

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

Edward Martz wrote:

But my heart sank. All my projects and important documents weren’t backed up, and there was no way I was about to delete everything.

Always back up your data! Time Machine is an excellent facility.

See:- Back up your Mac with Time Machine – Apple Support (UK)

This applies to everyone! 😎

Just sayin'!

I decided to end the call when the agent informed me that nothing could be done, so I took matters into my own hands and resolved backing up my files. A few hours later, I called back to speak with a different agent, who sounded more optimistic about troubleshooting, although I was still in the process of creating backups. I plan on calling again tomorrow, hoping to speak with someone more experienced who can help resolve the issue.

It happened to me on a 16" MacBook Pro 2021. Curiously enough, my work partition upgraded to 15.4 just fine, but my personal partition was stuck on 15.3.2. Reinstalling my computer was out of the question.

[Edited by Moderator]

Same issue....M1 Pro, could not update to 15.4; Safe Mode nor reinstalling Sequoia.

It works!

sudo softwareupdate --fetch-full-installer --full-installer-version 15.3.2 --launch-installer -R

Same here. The organization I work for has ~150 Macbook Airs. Most have upgraded without issue, but there have been ~20 that either reboot back to 15.3.2, or get stuck in recovery mode. For the ones that reboot to 15.3.2, I've had some success starting MacOS in Safe Mode and installing there. But the ones booting to recovery, reinstalling from recovery doesn't fix it. The most reliable way to get them to 15.4 though is to put them in DFU mode and restore them from another Mac.

Have you tried the DFU “Restore”? That’s what fixed things for me. It requires another Mac and “Apple Configurator 2” app (which is free in the Apple App Store). It resets your firmware and reinstalls the system. Many have speculated that this problem traces back to corrupted firmware.

I tried everything else with my M1 Max MacBook Pro and this is the only thing that worked.

There should be several posts in this thread about how to do it. The video below was very helpful to me as it steps you through the whole process. Video link here:

https://www.youtube.com/watch?v=q-FsB2onSx0

I hope this helps.

I’ve done literally everything. 15.4 doesn’t work on my M1 Pro so I just downloaded 15.3.2 from MrMacintosh website which installed without any hassle and works great.

I’ve heard that 15.5 is underway so hopefully that will solve this issue. I’ll just wait for 15.5 now and skip 15.4 I have already wasted 3 days.

Plus I donot know why apple is not talking about this issue which is so frustrating.

An Apple Apple Authorised Enterprise Reseller has successfully installed Sequoia 15.4 on my Studio M1 after several attempts... but after resetting the account password, I couldn't login any more: the new password was rejected, as well as the one they had set.

I found at Unable to install macOS Sequoia update 15… - Apple Community that updating the machine's firmware in DFU mode could help.

I've tried to update my Studio M1 firmare along the lines in How to revive or restore Mac firmware - Apple Support

But both the 'Revive Mac...' and 'Restore Mac...' buttons fail at each attempt with this message: The Mac "Mac" could not be updated because the firmware file was corrupt.

Disconnect and reconnect, then try again.

Apple, please help us get out of this quite annoying situation!

It's now a week my machine is unusable...

Same here, MacBook Pro M1. Only: Safe mode did not fix the problem, neither re-installing Sonoma...

Just updated to 15.4.1 and it worked!

If 15.4 didn’t work for you, give this one a try.