Mac mini (Late 2014) Will Not Update to macOS Monterey

Try accessing the installer using the link in this Apple article:

How to download and install macOS - Apple Support

If you still have issues, then try booting into Safe Mode to see if that allows you to download the installer. If Safe Mode works, then you most likely have some third party software installed which is interfering with the normal operation of macOS.

You should also be able to access the online macOS 12.x Monterey installer through Internet Recovery Mode using Command + Option + R. Unfortunately some Macs will only boot to the online installer for the OS which originally shipped with the Mac from the factory even when using this key combination.

In the past I've had better luck installing system updates from the Safe Mode because I evidently had some 3rd party software that interferes with the downloading and installing. I solved it by doing the following:

#1 - boot into Safe Mode according to Start up your Mac in safe mode - Apple Support.

NOTE: Safe Mode boot can take up to 3-5 minutes as it's doing the following; 

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

#2 - go to the System/Software Update preference pane and begin the download.

#3 - run the installer from the Safe Mode.

Did booting into Safe Mode help to run the installer?

I just read your original post again and noticed this bit:

makintracksusa wrote:

When I plugged my iPhone in, it said it couldn't link to it without the OS being updated, and a pop-up appeared for me to click to update, but nothing happens.

The update referred to when connecting an iPhone is not pertaining to macOS, but to a very small component which should normally take only a few seconds to install. Since you are also having issues upgrading to Monterey, this tells us your system has some sort of issue causing these problems. Upgrading the OS will not resolve this issue and will only make things more complicated. Since now you have your original problem as well as possible new software compatibility issues. The only place to get Monterey is directly from Apple....currently Apple is only providing the installer through the App Store.

Most likely some third party software is installed which is interfering with the normal operation of macOS. This is why we want you to try booting into Safe Mode to see if that allows things to work properly. Usual third party culprits are anti-virus apps, cleaning/optimizer apps, and third party security software....none of which are needed on a Mac. These types of apps also usually cause more problems than they they solve.

If the issue is not due to third party software, then sometimes a configuration profile can cause these issues as well. It may be a good idea to run the third party app EtreCheck and posting the report here so we can examine it for clues.

makintracksusa wrote:

Has anyone successfully update their mac mini late 2014 to monteray? I get 12.4 GB of the installer downloaded, then i get an installer error message. frustrating

What kind of error message you received when running the Install macOS Monterey app?

Has anyone successfully update their mac mini late 2014 to monteray? I get 12.4 GB of the installer downloaded, then i get an installer error message. frustrating

is there a download site for monteray where i can download a disk image to save and then use to update??

.

Are you running any VPN, Anti-Virus, or Cleaning apps?