My 2019 iMac is showing that OS updates are due (Monterey). It allows me to download the update but every time I try to install it it will get part way through the install and fails. It doesn't give a reason so I'm at a loss. It's been like this since the previous OS update. Currently running Big Sur 11.2.3.
When it fails, what message are you getting? Does the download finish? If it is failing during the installation phase, I am going to assume that you have used Wi-Fi to do the download. Some times Wi-Fi works fine, but often it does not. It is too slow for these very large downloads and corruption of the file occurs. Then it won't install. For OS installs, use a wired Ethernet connection and it often solves the problem.
iMac won't update from Big Sur to Monterey
