Hi, I am having the same notification and occasional "media card not supported" problem and the only way to get rid of it is to remove the SD card (!
.. On the same note, I noticed that "MediaServer" process is running constantly and eating my battery, every time the SD card is inserted...
Tried reformating SD card (64G, SanDisk), to no avail... Huston, we have a problem...

Tried reformating SD card (64G, SanDisk), to no avail... Huston, we have a problem...