I have a MacBook Pro m4 that is stuck in Recover mode.
The system has two Partitions one Sequoia, and one Tahoe system. After having the system booted into the Mac OS 26 partition, upon doing a restart back into the Sequoia partition, the boot up is apparently corrupted for both systems prompted by Recovery mode.
I never set up a recover Key my understanding was that a system password was basically the same. And so I did not set up a recovery “Key”
Is my ‘book dead in the water? is there some sort of Safe Mode work around?
Any chance there is still a Target mode to perhaps recover data on the drives?
Right now, fortunately, while on the Recovery page (after calming down a bit) I was able to choose the Mac OS 26 partition as startup in the Apple Menu drop down and the system did boot up.
I have run Disk First Aid on the Sequoia partition and can see the data which I am backing up which resulted in a Green check mark or such. I will try to choose the Sequoia drive (since most of my work stuff is on that, as startup disk after backing everything up.
If I can’t boot into Sequoia, at least I will have backed up data,
If Apple’s servers don’t let me install another Sequoia system, if the need arises, hmmm, that will be another juicy story to sort out … I’m feeling a bit paranoid since reading notes about how Apple is sort of forcing the Tahoe install update
**Apple is transitioning to macOS 26 (Tahoe), announced in June 2025, which includes firmware updates that may prevent M4 MacBook Pro models from booting into older systems like macOS Sequoia **
. Downgrading can cause Secure Enclave malfunctions, requiring full system restoration.
Forced Updates: macOS 26 (Tahoe) acts as a required update for newer Apple Silicon, including the 2025 M4 models, often due to firmware changes.
Downgrade Risks: Attempting to run macOS Sequoia on a Mac pre-installed with or updated to macOS 26 can lead to severe stability issues and Secure Enclave errors.
Compatibility: macOS 26 is designed to support M1, M2, M3, and M4, as well as 2019+ Intel Macs, but it acts as a “hard cutoff” for many older models.
If your machine is not booting, it is likely due to a firmware mismatch between the pre-installed macOS 26 and the older macOS Sequoia version, requiring a full reinstallation of the newer OS to restore functionality.
I am not an engineer, but my Dad was, So at least I know how smart I’m Not
I have to assume that the latest volume system update to Mac OS 26.2 bonked (that’s a little used engineering term) Sequoia, Firm-ly, on the head-Ware to smithereens-(yet another technical detailer)
P.S I gotta admit, … this scared the Uno-Wht outta me
P.P.S In the old days I would have sent this to Mr Ford, at Macintouch, I sort of doubt his contact in my email archives from 10 year’s ago are still working … certainly ties into his post
Yes installing Tahoe on a computer upgrades the internal firmware to Tahoe, but this will not prevent booting in Sequoia. The latest firmware is backwards compatible with previous OS, as far as the earliest OS supported by that machine.
There is no point in using Micromat or any other third party repair programme on an APFS system …it can and does only use the same fsck routine as First Aid.
To get the Sequoia install working again, without rolling back the internal firmware, erase the Sequoia volume pair and reinstall with a Sequioa bootable installer. If you try and reinstall from Recovery it will install Tahoe because you have Tahoe internal firmware. You can migrate your -Data volume back on the Sequoia install from a TM or other backup.
Thanks, I’ll take that under advisement for sure. Not sure it will be worth the time and effort, I was mainly using Sequoia while dabbling with Tahoe
Nothing really essential in terms of Sequoia, … I don’t think yet, I will have to see how some of my software fares in this in Mac OS 26
And not to belabor it, but I am 99.999% certain I did not manually install the Mac OS 26 latest update. And my Sequoia partition had been booting fine until I just happened to boot into the Tahoe partition this morning. My last boot was Jan 10, according to the system install log
This suggests that the simple operation of booting into Mac OS 26 invisibly updated the(any) firmware updates this morning. Not to mention Mac OS 26.2
There is only one reference to firmware, dated today: BackgroundActions: 0 firmware product(s) hmm
By the way, I only have Security Updates as the configured automatic update. The system updated to v. 26.2 somewhat secretly
This suggests that the simple operation of booting into Mac OS 26 invisibly updated the(any) firmware updates this morning. Not to mention Mac OS 26.2
This is very unlikely. The startup security checks since the advent of the separate SSV and Data volumes, and booting from a snapshot, have meant that Dual booting and external booting silicon Macs has been flaky from the start. Dual booting two OSes on the internal was always better than from external but IME sooner or later something like your experience happens, as well as signing in to Apple ID issues on switching. It has improved greatly since the early days, but I have stopped doing it.
BTW you mentioned that you saw the green check mark after running First Aid. It sounds like you had not expanded the “Show details” dropdown which appears on completion of First Aid. The top level green check mark simply means that the First Aid run was able to complete. The drop down details will show if there are problems. Warnings and errors in snapshots are not an issue as they will disappear as the snapshot is rolled out. The key things to look for are “The disk xxyy appears to be OK” or “The disk xxyy is corrupt and needs to be repaired” ….though I have had both on the same run!
Some (Most) of the APFS tech is well over my head. I don’t quite get the break up of a partition into its nominal, plus its Data volume. The nominal volume shows no errors in the results, nor indicators that repairs were necessary on both Volume, and Volume-Data
What you call the nominal volume is the read only System volume which is checked every build down do the last bit, and if the tiniest deviation is detected the machine won’t boot and you will be told to reinstall. If it passes the check a snapshot is made and the machine boots from the snapshot. So I am not surprised I have never seen an error or warning on the system volume or its snapshot. I have only ever seen warnings and errors on the -Data volume.
While I can’t seem to boot the Sequoia volume, can I navigate to a Library, or System files that might list the last known firmware for that boot drive?
I can certainly locate the firmware version on a booted drive via system profile, but perhaps it’s also kept in a log
your thoughts on how to navigate to which? file
later update: try as I might, my efforts have come up with the assumption that there is no actual file in which the firmware version would have been logged, as in an install.log or similar
The firmware is on the hidden iBoot volume, it is not on the System Volume or the -Data volume. The only way I know to see the version is in System Report > Hardware Overview which you can only see on a booted system of course. Not sure what you would do with the info if you could do as you ask. If you want to roll back the firmware you have to use DFU mode from another Mac as I posted earlier.
Not likely to roll back at this point, since I have all my data. I was just curious to see if I could track the version history to confirm what seems to be the case: that the current (updated) firmware for the OS 26.2 system (installed on MBPro M$) is not compatible with Mac OS 15 (Sequoia) That seems to be the result/information when inquiring via Google’s chatbot or AI
My thinking on that was that, perhaps, in install or boot up Logs there might be a reference to the firmware version.
Not essential, just a curiosity at this point.
p.s. I guess I will have to ignore the fact while I have Mac OS updates opted out of install, opting in only for security updates … somehow the firmware update must be part of Security and System Data Files protocol. … I did not manually install Mac OS 26.2
AI is wrong in this case. There are lots of people dual booting Tahoe and Sequoia. I have done it myself but not currently. Tahoe firmware does not prevent Sequoia booting.
I don’t know what is stopping your Sequioa booting but there are other reasons why booting fails especially in. Dual boot set up.
On my M1 Air, I have Sequoia and Tahoe and can dual boot with no issues. I maintain Sequoia due to the fact that iTunes 10.7 runs well on that OS where Tahoe mangled that version although other newer ones work I’ve heard. I use Sequoia for the most part anyway but installed Tahoe just to see what it looked like and if I need the latest OS version, I have it even if I don’t need it at the moment.
I had a similar problem with firmware as I had three partitions or containers at one point and deleted one as I needed the space and that caused some sort of a firmware issue as I recall. The tech at the Apple Store just reinstalled the OS at that time and I added a second container later and no issues after that.
My Sequoia partition goes directly to Recovery mode when opting for the drive when holding the power button
I can prompt the system install pane when clicking the actual Option icon. First Aid in that mode also has not revealed any anomalies … which to me is sort of another worthy conversation to have IMHO. I mean there is clearly an anomaly that cannot be repaired, except, presumably by reinstalling the system
Not sure I really want to revive the volume except as a curiosity at some point.
As I recall, First Aid cannot repair a firmware issue. That can only be solved be reinstalling the OS in DFU mode which is what they do at the Apple Store as I recall.
You might want to have two different OS versions just in case you really don’t like one. Many users don’t like Tahoe for example so carry on with Sequoia or older. Some older software might not work in later OS if Rosetta is deactivated so keeping an older OS is needed sometimes if your machine can support it.
As @jk2gs said I dont think First Aid will address all the types of issues that prevent boot. (I am assuming you have rerun FA with the ”show details” drop down checked, as earlier). FA can be run at Disk level but don’t know about repair. I have never seen a warning or error at Disk level. You could try booting the Sequoia installation into Safe Mode, but I wouldn’t hold out a lot of hope. The additional security checks in the boot sequence on modern macs can stop booting before any issues that safe boot and first aid would address.
EDIT Just after posting the above, I saw today’s article by Howard Oakley of Eclectic Light, explaining clearly how much happens before the file system is loaded.