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Does not open after the latest Apple Big Sur update last week. What to do? Receive a message at startup. The disk you attached was not readable by this computer. Eject, Ignore or initialize. None of these options will work for me especially the initialize which probably erase everything on the drive. Can this drive ever be opened again or maybe I need to go to another computer without Big Sur? HELP
iMac 21.5″, macOS 11.6
External and Internal Drive do die from time to time and without warning.
This can be very frighting if it occurs on an Internal Drive.
For this reason suggest - Do you have a Rescue Plan In-Place. This comprises having 3 Backups using 2 methods and 1 Off Site incase of Theft, Loss or Natural Disasters. A Time Machine Backup is very useful and can be used to Revert to Previous Working macOS. For addition purposes - two Tested Bootable Clones each to separate external drives. This is insurance incase the upgrades goes sideways. At least one Tested Clone and / or Time Machine Backup should be Off - Site
Credit for above Rescue Plan, has come by observing similar suggestions from a Contributor participating this Question. Thank you.
External and Internal Drive do die from time to time and without warning.
This can be very frighting if it occurs on an Internal Drive.
For this reason suggest - Do you have a Rescue Plan In-Place. This comprises having 3 Backups using 2 methods and 1 Off Site incase of Theft, Loss or Natural Disasters. A Time Machine Backup is very useful and can be used to Revert to Previous Working macOS. For addition purposes - two Tested Bootable Clones each to separate external drives. This is insurance incase the upgrades goes sideways. At least one Tested Clone and / or Time Machine Backup should be Off - Site
Credit for above Rescue Plan, has come by observing similar suggestions from a Contributor participating this Question. Thank you.
chocobill wrote:
Does not open after the latest Apple Big Sur update last week. What to do? Receive a message at startup. The disk you attached was not readable by this computer. Eject, Ignore or initialize. None of these options will work for me especially the initialize which probably erase everything on the drive. Can this drive ever be opened again or maybe I need to go to another computer without Big Sur? HELP
How is that external drive formatted?
If NTFS update your third party software...
paragon
tuxera
there are otheres
chocobill wrote:
Does not open after the latest Apple Big Sur update last week. What to do? Receive a message at startup. The disk you attached was not readable by this computer. Eject, Ignore or initialize. None of these options will work for me especially the initialize which probably erase everything on the drive. Can this drive ever be opened again or maybe I need to go to another computer without Big Sur? HELP
What happens with the computer is started without the drive attached ?? Then connect the problematic drive Directly to the computer ?? Does the issue present??
Thanks, I've had this external drive for many years. Started with my old Microsoft PC. When I switched over to Apple, I initialized to change the format. It's worked for many years (8) until this latest update. I've sent the question to Western Digital this morning. So far, no response. I was afraid that if I chose the initialize when trying to open it up, it was erase everything that's on the drive. I believe it's NTFS. - It's worked through all the Apple updates for years. Thanks
I tried your idea. Same problem with the same error message. Tried my old computer with macOS Catalina version 10.15.7 OS no luck with that computer either. Seems like it's the external drive?
Western Digital External Drive Doesn't Open
