Unable to upgrade macOS

Cannot upgrade from MacOS 26.0.1

I have an M4 Mac Mini which I can't update beyond Mac OS 26.0.1. I have tried MacOS 26.1 . When I run the update the Mac appears to go through the motions of installing but at the end of the process we are still at 26.0.1. I have tried both Software Update and the command line.

The only unusual factor is that I am installing on an external drive which I assume is allowed, this is essential now that it is not possible to upgrade internal drives.

Any help appreciated.


[Edited by Moderator]

Posted on Nov 21, 2025 11:32 AM

Reply
5 replies

Nov 21, 2025 11:46 AM in response to Gordon Maynard

Gordon Maynard wrote:

Cannot upgrade from MacOS 26.0.1
I have an M4 Mac Mini which I can't update beyond Mac OS 26.0.1. I have tried MacOS 26.1 . When I run the update the Mac appears to go through the motions of installing but at the end of the process we are still at 26.0.1. I have tried both Software Update and the command line.
The only unusual factor is that I am installing on an external drive which I assume is allowed, this is essential now that it is not possible to upgrade internal drives.
Any help appreciated.

[Edited by Moderator]


dis able any firewall you may have set in >System Settings

Change Firewall settings on Mac



unplug all non-essential peripherals when testing

Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus

all known to cause issues on the macOS


try from a A SafeBoot Start up your Mac in safe mode - Apple Support

Login and test.


Unable to upgrade macOS

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