My question is identical to this, but logging in and out did not solve the issue.
https://discussions.apple.com/thread/251264910?login=true
The device is a usb. When plug it in I get
If I go to disk utility I get this
I cannot perform any of the options there. I can see the usb under hardware, but that's about it. Also, I tried mounting form recovery mode and this didn't work either.
Hey there!
Thanks for reaching back out to us and for updating us. You've done a great job in troubleshooting this specific issue. It sounds like you feel that your external hard drive might be the issue. The best approach to take is to test your accessory with a different computer. We understand that you currently don't have access to one. Whenever you do get access to one, you can try to connect it there and see if it lets you erase it. Just in case, we do have a helpful resource for when facing issues with your USB accessory on Mac:
If a USB device doesn't work with Mac
If the same error populates on a different computer, you might have to contact the manufacture of your external hard drive for help.
Thank you for using Apple Support Communities.
Hey there!
Thanks for reaching back out to us and for updating us. You've done a great job in troubleshooting this specific issue. It sounds like you feel that your external hard drive might be the issue. The best approach to take is to test your accessory with a different computer. We understand that you currently don't have access to one. Whenever you do get access to one, you can try to connect it there and see if it lets you erase it. Just in case, we do have a helpful resource for when facing issues with your USB accessory on Mac:
If a USB device doesn't work with Mac
If the same error populates on a different computer, you might have to contact the manufacture of your external hard drive for help.
Thank you for using Apple Support Communities.
Hi,
I don't have another computer to try it on but other USB drives work on this mac. Yes, it has worked in this mac before. It's 16gb but as U can see in image, Disk Utiliy only shows 2.5 Mb.
If I do First Aid it says successful but doesn't change anything, maybe b/c part of disk in inaccessible. I tried this.
I've also tried to erase it using Disk Utility erase but the it gives and error because it is not mounted. If I try to mount it I get the original error. Maybe the usb is fried.
Hello ARSSONIST.
Thank you for using Apple Support Communities. It sounds like you're unable to use your USB accessory with your Mac. Specifically, you're getting prompted an error message saying that it's not readable by your Mac. If this is the case, we'd like to look into this issue with you.
Has this USB accessory ever worked with your Mac before? If you connect your USB accessory to a different Mac, does this specific error message continue to populate? This information can help us further isolate if this issue is linked to your USB accessory or your Mac.
We did see in the screenshot you shared with us that you're able to see your USB accessory in Disk Utility. If you select "First Aid" what happens? If you haven't tried that yet, try repairing your disk:
How to repair a Mac disk with Disk Utility
Repair a storage device in Disk Utility on Mac
If there isn't any important data on this USB accessory, you can try to erase it and reformat it using Disk Utility. Just in case, the following link has more details on how to accomplish this task:
Erase and reformat a storage device in Disk Utility on Mac
We hope this information is useful. Best of luck.
DiskManagement.disenter error -119930868
