macOS 13.2.1 update won't install - no errors

azrael wrote:

I'm seeing very unexpected behavior trying to install the 13.2.1 update on a friend's 14-inch M1 Pro MacBook Pro (currently running 13.2).

The system has found the update and claims that it's ready to install. i.e. it isn't also trying to download it. When I click the button to install, it prompts for the Mac password and then reboots (on at least one occasion, the update has been interrupted by another password prompt from Software Update - no clue why there would be multiple prompts). The update does not install and does not indicate any error or problem during installation, so this doesn't apply.

After returning to the Desktop, the system again prompts for the Mac password to install the update. Lather, rinse, repeat. I'm told that this has been happening for over a week. Since Apple doesn't release updater files anymore, I can't bypass the Software Update process like I would have in the past.

Any suggestions on where to look or some cache to reset?

There are at least 5 options to try from your link above—so you are saying you tried them all...(?)

typically—running the installer/update from a Safeboot  How to use safe mode on your Mac - Apple Support sorts most issues here.

if no progress, try from the Terminal app update using the command line, copy and paste:

sudo softwareupdate -i -a -R

note on the -flags:

-i Install

-a All appropriate updates

-R Automatically restart (or shut down) if required to complete installation)