Can't update to 12.5.1

There are factors:

1 - Like poor Wifi connection

2 - Slow wifi connection

3 - Too many other people downloading at the same time and Apple Severs are overloaded

4 - Software on the computer interfering with the download process including AntiVirus Software

Notation: Disabling the AV Software may or may not solve the issue. Removal of the AV Software may increase the chances of the download to perform as expected.

5 - Running behind a VPN which may increase Packet losses or corruption of the download 

6 - If via wifi too many Other devices using the wifi at the same time reducing the Bandwidth to your computer. 

7 - Best Results are via Ethernet Cable to Router

8 - Restart in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts. The boot up will be slow and can take some time - Normal and Try Again using the Software Update Applet in System Preferences

9 - Worst case - Restart in Recovery Mode and choose Reinstall macOS. This in theory will pull the latest version of Monterey available and commence the installation.

Sorry but still missing crucial piece of requested information .

Barring that info being provided -->>

1 - Get Support Choose a product and we’ll find you the best solution. Start now

2 - My Support. Get up to date information about your Apple products in one place including repairs, tech support cases, and much more. Sign in to My Support

Four things --- >>

1 - Is this computer Owned by a Company, University or Organization which has Enrolled this Computer in a MDM ( Mobile Digital Management Service ?

2 - If yes to above - all Bets gets are Off for any type of update as the MDM Controls whatever and / or even if the update can be installed

3 - Provide a Screen Shot of ( About this Mac ) without the Serial Number appearing in the image

4 - Example of requested information in below image

EDITED

This "9 factor" post is listed everwhere ...not helpful. Apple announces a security issue but the software update does not work on 2019 MAC following steps 1-8. IF clean install is only way to update... Apple has once again stiffed its customers.

In this specific case and as an exception, will offer additional assistance to a User who is not the Owner of this Question.

Understand, we are all working Remotely from all around the world. 

Therefore, we do not have the On-Hands experience the User ( you ) has with this computer.

The next best thing for us to having a semi - actual On-Hand experience on this computer is to follow the steps below

Download the Application Etrecheck directly from the Developer.

The application is free or paid from added features. 

It will take a Snap Shot -  both the hardware and software.

 The Report will Not Reveal Any Personal Information. 

Post back the Full Report - copy and paste - using the Additional Text Icon ( 3rd Icon to last )

We can have a look at the report for possible issues and may have possible suggestions to resolve the issues.

I'm having the same problem, but trying to update from 12.5.1 - 12.6. Besides the OS, it's trying to download command line tools for Xcode 14 (why I have to upgrade OS) and Safari 16.

Restart Now -> Downloading Updates -> Repeat the previous.

It's a build server, a 2013 Mac Pro (yes, still running, still eligible for updates). We've updated a more recent mac mini, that worked without issue. A bit hard to try safe mode, as I'm remoting into the Pro, but it's not clear that that works in any case. Have rebooted, that didn't help either.

Terminal and below command without quotation marks

" softwareupdate --list-full-installers "

If v12.6 is listed good

Terminal again without quotation marks

" softwareupdate --fetch-full-installer --full-installer-version 12.6. "

The last command will download the Full Version and place a new Application is Applications Folder called " install Monterey ( 12.2 GB Size )

It does not auto launch

The user needs to launch it like another application and in this case follow the prompts.

First command: v12.6 listed, so yay.

Second command: The period at the end resulted in a failure. Removed the period and it worked; in fact, it's running now and claims to be installing:

$ softwareupdate --fetch-full-installer --full-installer-version 12.6
Scanning for 12.6 installer
Installing: 18.0%

Will update after it's finished (slow Pro; long install)

Same exact results as spinako.

1 - Is this computer Owned by a Company, University or Organization which has Enrolled this Computer in a MDM ( Mobile Digital Management Service ?

No.

2 - If yes to above - all Bets gets are Off for any type of update as the MDM Controls whatever and / or even if the update can be installed.

N/A.

3 - Not needed, see below.

Have requested a call via Get Support. That and My Support are a bit tricky; I don't log into any of our build nodes as me, rather via a service account. I did log in with that account to Get Support, which showed all the Apple devices, past and present, EXCEPT the one with the problem! Thus, requested the call. Also, because I mentioned it was trying to update all three items (OS, Xcode, Safari), it focused in on Safari being the issue. Automated systems: Shorter, faster, and wrong (sometimes).

Fingers crossed.

spinako, the missing bit was the serial number, which P. Phillips cut off in his screenshot.

Went into the office to fiddle with it. I may have a breakthrough here.

In the Restart Now dialog, there is a details button (or the like; sorry, don't have it at hand now). That shows you want's being updated. I unchecked Xcode and Safari and...the OS update started.

Give it a whirl.

It was from preferences -> update software. For me, anyway, there is a button about Details. It listed the 3 items, with checkboxes, so I was able to uncheck Xcode and Safari.

macOS 12.16 is definitely installed. Also...I had downloaded Xcode from Apple Developer downloads, and expanded it and renamed it (we keep 3 versions of Xcode on our build nodes). The update software thing popped up again, with safari and xcode; tried to run it, but it said, for both (IIRC) that the installer had disappeared. Xcode was there, but had to use it to download and install the command line tools. Safari seemed to have followed a similar path; it's on 16 however, so all's well.

Fingers crossed for your efforts!

Hi,

Try booting into Safe Mode: How to use safe mode on your Mac - Apple Support and see if it will update there. If not, boot normally and try again.