Various causes: There are very many causes, from congestive heart failure, to lymphedema, to venous insufficiency, blood clots, pregnancy, a various other causes, including serious and not-so-serious causes.
I have a Sony DVP ns55p blu-ray player with a usb port in the front. The player requires that the usb flash device (thumb drive) be formatted in FAT32in order to recognize it.
SanDisk announced the second generation of its USB-C flash drive at Computex, and it's faster, retractable, and now there's a 128GB version. The SanDisk Ultra Dual Drive USB Type-C flash drive features USB-C and USB-A connectors, which can be accessed by using the slider on the side of the drive. SanDisk has improved transfer speeds, which now reach up to 150MB/s thanks to USB 3.1.