User profile for user: Falko Zurell
Falko Zurell Author
User level: Level 1
23 points

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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User profile for user: crazyl999
crazyl999
User level: Level 1
26 points

Posted on Apr 1, 2025 9:59 AM

I’ve had the same problem, except mine is with two different volumes on the internal SSD on my M1 Macbook Pro. My work side updated absolutely fine, but I was unable to update my personal side - it rebooted in a similar way to yours, but then just had an “We ran into a problem” style prompt with the option to report.


As there are a fair few vulnerabilities addressed with this update and I had not rebuilt my personal volume since I got the device, I thought I’d try installing from scratch but I’m hitting the same problem with just trying to install the OS on the separate volume, it doesn’t complete successfully and now I’m stuck with just my work volume.


Planning on doing some more troubleshooting at the weekend when I have some more time, but this isn’t ideal.

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macOS 15.4 update failed on external disk

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