I just got a brand new Seagate Backup Plus 3TB and tried to mount it on to my DIR-850L.
But my router won't recognize the Seagate Drive even thou Seagate is linked and powered on!
I even tried formatting the Drive to default settings by plugging it directly into my PC, but my router still doesn't detect it once plugged into it.
BTW, using 8GB Kingstone USB Drive work without any problem with DIR-850L.