After using SanDisk SD cards for at least two years on a PC, first with Ubuntu 16.04 and more recently 18.04 today I was unable to "open" an SD card though visible in "Files". The data had been entered onto the card by the same PC.
I fished out my old 2004 MacBook Pro and the card behaved normally in the Mac, I even formatted it as FAT but back in my PC under Ubuntu, though it seemed to be working again (I copied a file to it and was able to open it) I couldn't format it.
On requesting a Ubuntu format on the first mask I could choose NTFS (already chosen by the system) or FAT but on clicking on "Next" nothing happened whether the choice was NTFS or FAT.
Finally I rang SanDisk and they simply said that they didn't support Linux!
Does anyone know of any Linux supported SD cards?
Bob
I have several USB pendrives and SD cards made by Sandisk, and they work for me in Ubuntu 18.04.1 LTS.
There may be some data in the first mibibyte, that are confusing your tool(s), so that they fail. I suggest that you install
mkusband use it toeither wipe the first mibibyte with mkusb and then use another tool (e.g.
gparted) to create a partition table, partitions and file systems, that you want,or restore the card to a standard storage device with mkusb (quick and easy, you get an MSDOS partition table with one partition with a FAT32 file system).
If this does not work, I suspect that there is a problem with the card reader/adapter (that it does not cooperate well with Ubuntu 18.04 LTS).