trying to install Big Sur on 2019 27” iMac. Endless errors and reboots, now I am not able to set Macintosh HD as startup disk (SDErrorDomain error 104) I keep ended up on recovery screen. Reinstall OS shows only Big Sur, which will not install. I am in a loop as it will install ⅔ and then go back to recovery mode.
And no, I dont know what I am doing. I have NEVER had an update end this way
iMac 27″, macOS 10.15
The only thing that worked for me was to erase macintosh HD and macintosh HD data and eventually was able to connect to internet recovery which reinstalled mac OS Mojave - before erasing, I used target disk mode and copied my user file so as not to lose data. I am just grateful that mojave is working and my hardware was not damaged. It will be quite some time before I attempt Big Sur.
The only thing that worked for me was to erase macintosh HD and macintosh HD data and eventually was able to connect to internet recovery which reinstalled mac OS Mojave - before erasing, I used target disk mode and copied my user file so as not to lose data. I am just grateful that mojave is working and my hardware was not damaged. It will be quite some time before I attempt Big Sur.
Hello rootoomuch.
Thanks for reaching out to Apple Support Communities. We understand that you are receiving an error when attempting to install Big Sur. Keeping your macOS up to date is important, and we will be glad to assist.
Let's create a bootable installer to see if that helps: How to create a bootable installer for macOS
Cheers.
Thank you for your response. I have ended up back with Mohave and will avoid Big Sur for awhile. I ended up doing internet recovery.
When I am brave enough to attempt Big Sur again, I will try your suggestion.
thank you again
Any solution? I am facing the same issue. Please help
SDErrorDomain error 104
