macOS 15.4 update failed on external disk

All drives had 15.3.2 I booted each one up and then applied the 15.4 update as any normal process would follow.

And the problem also occurred on a clean installation of 15.3.2 after the above. Which means that 15.4 changes the Firewall settings on Mac

Exactly the same. I believe that it will be fixed quickly and 15.4 will finally be released on the Appstore which until now did not exist !

We have installation issue 15.4 on external drive to MacBook Air M1

which one Mac model you are using

All my external drives have FileVault on and no issue with updating so I suspect some other issue preventing others from updating.

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!

Apple support were unable to resolve on the phone after trying another method of erasing the internal drive, so I need to take it in to the Apple Store for a service appointment, device is effectively a paperweight now.

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

Falko Zurell wrote:

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.

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.

I ended up going to 15.3.1. my drive was up to date, and 15.3.2 never showed. only 15.4. m1 mini. I also just tried signing out of iCloud on each drive, and installing on internal/external. same error. guess Ill wait till 15.5, and try again.

I have 15.4 on my internal drive APFS. I made two external TB drives as boot drives (clone of my internal) and no issue using neither one. All my external drives are APFS with FileVault on.

my problem is after upgrade to 15.4, my M4 Mac mini can't boot from external SSD , it just shows a blank screen and keep reboot for a while. I have reinstalled the OS, and still get a blank screen.