Updated Mac software will not complete update
Updating macOS frozen for 24 hours
iMac 27″ 5K, macOS 10.15
Question marked as
Hold {pwer button in until it shuts down, then...
Start up from macOS Recovery
To start up from macOS Recovery, turn on your Mac and immediately press and hold ...
Command (⌘)-R
Installs the latest macOS that was installed on your Mac.