Failed Upgrade Big Sur iMac (Retina 5K, 27-inch, 2017)
Hello.
I’m trying to install Big Sur, as prompted by my iMac. It downloaded OK, and took me through licence accepting etc.
It then proceeded to a black screen with Apple logo and a progress bar. The progress bar is stuck at about 10%.
The machine is stuck in a loop of restarting, perhaps every 1-2 minutes. The mouse pointer appears top left after a short delay.
It has been like this for 4 hours.
I tried forcing power down with power button, then restarting. No change.
Any thoughts welcome!
Thank you in advance.
iMac Line (2012 and Later)