So you have a MicroSD adapter that has a MicroSD card in it, that fits into a normal SD card slot?
How old is the card reader and how old is the MicroSD card? It seems that not all the old card readers can read the newer higher capacity cards.
I no longer use the MicroSD Adapter, I have a card reader that has a slot just for a MicroSD card and that way I know it will work everytime