I have tried 2 different computers, 2 different cables, and 4 different USB ports (3.0 and 2.0). Windows 10 and Windows 7 see my tablet and card as a media device (per Android's new way of doing things), and I can browse the card and the tablet in Explorer. I can even copy files to the sd card in Explorer.
What I cannot do is ANYTHING in MC. It detects the 2 devices, but when I click on them it says 0 bytes of memory. Both the tablet and sd card say this. I even tried a different sd card as well. I even put a couple of songs on the card in Explorer and then ran MC and it wouldn't work.
I have the latest version of MC 21. I have scoured web sites for days, and none of the suggestions seem to work. I have even installed the Samsung drivers that have been suggested, but this does not work either. It seems to me to be strictly a MC problem, as Windows 7 and 10 both see the devices and can copy to them.