Cannot update MacOS (Big Sur to Monterey)
There's a notification alert on my Software Update icon. But for several weeks now, when I click on it, the Preferences window just goes into a permanent "Checking for Updates" spin.
I have a MacBook Pro (Retina, 15-inch, mid-2015). According to the Apple website, it is compatible with Monterey. Currently running Big Sur (MacOS 11.6.1). I have a 500GB hard drive with 200GB free space.
I have tried restarts (multiple times) and shutting down all other applications. I can't even back up my iPad anymore because now that the latter is running iOS 15.2.1, apparently there's some kind of incompatibility. When I try, a dialogue window tries to download an unspecified update before the iPad backup can proceed, but the bar never progresses beyond a dot.
I am assuming the iPad problem is linked to Big Sur. Would appreciate any help anyone can suggest.
MacBook Pro 15″, macOS 11.6