Chosen Solution
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
You’ll need to give a file recovery app a try like Data Recue 5 After you salvage your stuff you’ll want to re-format the SD back to exFAT. You really want to leave it running exFAT.
maybe try mounting it with terminal diskutil list then find your sd card in the list and type sudo diskutil mount diskXsX where x is the disk and partition number
Just try to plug it in other mac with lower system if its readable, so you may know if the sd card has the problem or your system. because i have an issue with my external HDD cannot be read in 10.14.2 but readable in 10.11 and 10.12.
