S7 device upgrade April 2017. Micro SD from Razr put in S7 and readable. Just noticed "SD card Not Inserted" in My Files display, but MicroSD still in tray & has not been removed since purchase. Last software update (G930VVRU4BQG1) applied 8/3/17. Do not know if MicroSD card visible between software updates; I know there have been at least 3 if not more updates done since April purchase. I have reinserted MicroSD & rebooted multiple times and still MicroSD not found by my S7. Please help as soon as possible!!