(WD Elements Play 2TB - video thumbnail does not work!

I have a problem with video miniatures (WD Elements Play 2TB).
I copied into my video folders images folder.jpg (ech folder its own folder.jpg). I set the thumnail view in video options, but thumbnails not showing. I tried several formats (bmp, jpg, png). 
Firmware was updated (last oficial firmware).

I have the EXACT same problem…can someone help overcome this???

I mean the firmware ws update from having video previews to now having thumbnails…but what was the point if WD doesnt support it properly or explain how to set the whole thing up so it works…All you see is folder icons, no images whatsoever, its extremely frustrating wasting so much time experimenting, trying to figure out why.

I can see from this forum that its such a simple procedure for other WDTv units…

Please help if u know how.