Hi,
I have a Samsung EVOPlus '''256GB''' microSDXC card that I bought new, and formatted (Apple HFS on MacBook Pro 13” 2015 with MacOS 10.14.2) and was able to use for a few days fine (although it seemed a touch slow).
Now my computer is unable to mount the card (“This disk is not readable'“), although it shows up in Disk Utility as a greyed out internal physical volume with a capacity of '''268.44GB'''. I’ve tried First Aid, but it says there’s an “Invalid key length”.
The stuff (about 3GB worth) on here hasn’t been backed up anywhere else yet, so I really want to try and save it all.
Any advice or tips? I don’t even understand how the system suddenly decided the card gained an extra few gigs!?
Thanks for any help you can give,
H