macOS 15.4 update failed on external disk

I've got a maybe somewhat odd setup here. MacBook Pro M2 Max with macOS Sequoia 15.4 running on the internal SSD (APFS, encrypted). In addition I have an external NVMe SSD (Samsung T7) where I've also installed macOS Sequoia to be used as StartUp-Disk if need be. With that setup I keep my private and my corporate macOS installations physically separated. "Just" using the same MacBook Pro to run them.


Now I tried to apply the latest update from macOS 15.3 to 15.4 on my external SSD. The update shows, the external disk is set as StartUp Disk and the update process starts. It looks like it does the update with multiple reboots and all. But after it's finished and log in to the macOS it still shows the update 15.4 as available. There were no apparent errors during the update process. But I noticed that wen I log in after the update the system complains that it was improperly shut down and whether it should report that.


Any idea how to debug this? The update worked just fine on the internal SSD without any issue.


MacBook Pro 14″, macOS 15.4

Posted on Apr 1, 2025 5:54 AM

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Posted on Apr 2, 2025 11:53 PM

Just tried it again and it fails. After startup I get the message that the machine was shut down unexpectedly. Saw the following error message in the details that are going to be send to Apple:


panic(cpu 8 caller 0xfffffe001bfbad28): /AppleInternal/Library/BuildRoots/17229e79-0523-11f0-a80c-fe9e33ca05fa/Library/Caches/com.apple.xbs/Sources/apfs/kext/apfs_filter.cpp:1713 Assertion failed: !(cpOffset % CRYPTO_SW_BLKSIZE)
Debugger message: panic



Looks like an issue with the Installer.


I do NOT have the decryption key for my internal SSD in my keychain in the macOS booted from the external disk. This is deliberate to not have access to the Internal SSD by default. Maybe that's of an issue for the installer that one of the disks (the internal SSD) is encrypted and requires a password. Although that disk should not be touched by this update.

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Apr 2, 2025 12:32 AM in response to crazyl999

just out of curiosity... is your personal volume using a case-sensitive filesystem? Because I just recalled that this is the one major difference I have. My internal SSD is just normal APFS, not case sensitive. The external SSD is APFS with case-sensitive filesystem. Dunno if that could be the issue.

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Apr 2, 2025 8:17 AM in response to Falko Zurell

Ditto, it didn’t work for me either. I’ve now gone the nuclear route of wiping the entire drive as I have time machine backups of everything, and would like to get my personal volume fixed. Prior to this I tried a first aid repair via disk utility in the recovery menu as recommended elsewhere but I still am unable to install macOS, either from recovery or USB.


I’ve just had a phone call with apple support who directed me to try wiping the device via the password recovery assistant, and I am currently a reinstallation from recovery which will hopefully be more successful!

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Apr 3, 2025 1:42 AM in response to crazyl999

Hi,

I have similar problem on my 14" MacBook Pro M1 Max 2021...

Error message with "panic" message after upgrade to latest Sequoia. So I decided to do full recovery to only available Sequoia.

Recovery started normally, restarts automatically and after reboot it displays dialog to select startup drive. When I select Macintosh HD it says that system must be reinstalled.

I tried erase disk, erase Mac, installation on external SSD with the same result.


Apple support told me that only solution is diagnostic on service center. But I don't think my HW is faulty. It worked fine until latest Sequoia update.


Do anybody make any progress with this issue please? Do you have any information from Apple about it. Do they some inquiries regarding this behaviour?


Thanks

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Apr 3, 2025 11:14 AM in response to ameenjuz

M1 Mac mini. Lost a tb of external drive o was running os off for 3 years. Today I got 15.3.1 installed. Same thing happens on 15.3.2 I beleive. 15.4 I have attempted several different things, and still starts up saying is restarted error. I’m not installing on the onboard drive till there’s a fix. Ordered me another ssd so I have one try try updates first in the future. Set my work back a few days.

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Apr 11, 2025 4:46 AM in response to Falko Zurell

Well glad to see there are a number of us with unusual setups.


Mine is Mac mini M2 Pro, bootable from external drive.


As with others, the internal drive updated to 15.4 no problem (as did my backup M2 Mini), but not the external drive. In 2 profiles, I have tried updating multiple times, in standard mode and safe mode. On the spare profile it goes through the procedure, but afterwards still on the old version, on my main profile I get the dialogue box saying my Mac has restarted after a problem.

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macOS 15.4 update failed on external disk

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