Re: SD Card
Welcome to Android Central! Sometimes microSD cards don't work because of a problem with the device, and sometimes they don't work because the card is faulty or counterfeit. What devices are you using? Emerson tablets are very much budget devices, and so their hardware or firmware may not be of the highest quality. If it's the Emerson tablet that can't read the SD card, my guess is that it's a problem with that tablet, not the card. Make sure the tablet's operating system is fully up to date by going to
Settings>About Tablet>System Updates. You might also find updates at the Emerson support website. The other option is to contact Emerson and inquire about warranty repair or replacement.
To check if your microSD card is counterfeit, install
SD Insight on the tablet that works--this app can tell you the exact details about the card.