MacOS Big Sur Update
I have a 2017 iMac and just did the update. My iMac started the update and then restarted. After which the Apple logo appeared with a notification “about 28minutes remaining”. Then it went to another screen with macOS Update Assistant in the top left hand corner. A tab popped up with “ An error occurred applying the software update”. The only option being to select ok as I cannot exit this screen. After selecting ok another tab opens saying “Choose Startup Disk” and then an option to select only my second hard drive and restart or to “click to restart this computer in target disk mode”. Any idea how I can fix this?
iMac 27″ 5K, macOS 10.15