I have been trying to figure this out for a while now! I have a 32gb Kingston DTSE9 USB 2.0 flash drive, that my mac cannot view or read at all. It does not show on the desktop or in finder, and partitions are not shown in disk Utility. I can run first aid, which works fine but then erasing, restoring or partitioning fails every time. I am pretty savvy (software developer) but cannot get to the bottom of this. I have lots of other flash drives hanging around, so do not need this to be fixed but I do hate wasting hardware. Any ideas?