justinfhersey :
I bought this MicroSD Card New from Ebay. I had it in my Android Phone and never had any issues with it. For Christmas i got a new Android Tablet (LG G Tab 8.3) and it started doing this. I formatted it and check it for errors. It works for a while and then it does this. Idk if the card has went bad or not. Ive also reset the tablet so it shouldnt be the tablet.
It seems that the MSD is corrupting. Eventually the card will not be readable. Try formatting the card in a desktop/laptop and use it there for a while to see if the problem occurs or use the card in a mobile.
I had a similar issue whereby my files were no longer being read in my S3 which in turn was no longer detected in Windows. Sandisk card which was less than a year old, failed on me. Unfortunately Sandisk wants the original bill of purchase to RMA the card.